thin perhaps not as good as i thought

[Gokhan]

Originally Posted By: Trav
Quote:
Modern gasoline engines should do OK with any oil from 0W-20 to 20W-50 and with any certification

Under the operating conditions these engines are running under this is false.
Anything 20w is not recommended in engines running under these conditions.
With modern synthetics 15w40 and 20w50 are for the most part obsolete weights in gasoline engines (granted there maybe some racing apps or older air cooled).

Quote:
One thing that may be is that when you changed the oil type, the antiwear films on your rings/cylinders got modified. That may sometimes cause temporary problems until new films form

That's really stretching it thin.

If you read his original post, his ASX owner's manual is recommending anything between 0W-20 and 20W-50 for his climate. (Of course, you shouldn't run 20W-50 in subfreezing temperatures.) Also, Toyota for example recommends anything between 0W-20 and 20W-50 for most of its cars sold in Europe. Toyota recommends only 0W-20 for exactly the same cars sold in US.

My guess, explained in my post above, is that he doesn't have a problem at all.

 

[OVERKILL]

Originally Posted By: chiks
Originally Posted By: OVERK1LL
Originally Posted By: chiks
How is air coming out of the oil filler cap considered as blow by?


Because that's air/combustion gasses from the crankcase, that has made its way past the rings.


These gases will come out of intake or exhaust valves. How does it comes out of the oil filler cap?


I'm not sure you understand how an IC engine works.......

 

[Trav]

Quote:
0W-20 and 20W-50 for most of its cars sold in Europe

You do know Germany is in Europe right?
0W20 or 5w20 is spec in nothing Toyota or otherwise except hybrids.

His owners manual is for Holland, these engines take ESP 5w30 when sold in Germany with an HTHS of 3.58. If he is operating the car in Germany under German autobahn conditions he should be using German spec oil.
He said he does run the WOT for extended periods so he could easily use New Life 0w40 with an HTHS of 3.8.

KIA Rio 1.25 1. Wahl Mobil 1 ESP Formula 5W-30
Kia Picanto 1.0 1. Wahl Mobil 1 ESP Formula 5W-30
Mitsubishi ASX 1.6 1. Wahl Mobil 1 ESP Formula 5W-30

BTW i have bought more than a few "grey market" vehicles from Holland and had to use German spec oil because i lived in Germany not the ones spec'd in the Holland owners manual.

You know you thin oil guys live on a one way street. If a Euro car comes to the US you have no problem recommending thin oil because the driving conditions are different and there is no Autobahn in the US and Canada.
Well he is driving the autobahn and that thin stuff could ruin his engine in time. It is a two way steet.

 

[KrisZ]

Originally Posted By: Trav
Quote:

One thing that may be is that when you changed the oil type, the antiwear films on your rings/cylinders got modified. That may sometimes cause temporary problems until new films form

That's really stretching it thin.


Really thin, like all the wonderful claims made in Toyota 0w20 thread.

While thin oils have no problems in NA, where speed limits are low and engines have enough displacement and power not to be stressed, Europe, with small engines and higher speeds is something different. Also, since most cars are manual, they are revved higher between gear changes even at slow speeds. That is why all these blanket statements about thin oils are so dangerous.

 

[Gokhan]

Originally Posted By: Trav
Quote:
0W-20 and 20W-50 for most of its cars sold in Europe

You do know Germany is in Europe right?
0W20 or 5w20 is spec in nothing Toyota or otherwise except hybrids.

His owners manual is for Holland, these engines take ESP 5w30 when sold in Germany with an HTHS of 3.58. If he is operating the car in Germany under German autobahn conditions he should be using German spec oil.
He said he does run the WOT for extended periods so he could easily use New Life 0w40 with an HTHS of 3.8.

KIA Rio 1.25 1. Wahl Mobil 1 ESP Formula 5W-30
Kia Picanto 1.0 1. Wahl Mobil 1 ESP Formula 5W-30
Mitsubishi ASX 1.6 1. Wahl Mobil 1 ESP Formula 5W-30

BTW i have bought more than a few "grey market" vehicles from Holland and had to use German spec oil because i lived in Germany not the ones spec'd in the Holland owners manual.

You know you thin oil guys live on a one way street. If a Euro car comes to the US you have no problem recommending thin oil because the driving conditions are different and there is no Autobahn in the US and Canada.
Well he is driving the autobahn and that thin stuff could ruin his engine in time. It is a two way steet.

Toyota Auris, for example, specifies all viscosities between 0W-20 and 20W-50. So, it's not only Prius.

Is there any other country in Europe where the freeways don't have speed limits? Why would anyone try to drive a car with a 1.0-liter engine on the left lane of a German autobahn where some BMWs want to go 140 MPH? From what I heard, few people drive that fast there anyway, and the typical speed on the left lane is not much different than in the US (about 75 MPH in US when there is no traffic). So, the whole "autobahn" issue only applies if you have a BMW-like car and autobahns in your area actually don't have traffic.

 

[Gokhan]

Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.

High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.

If the load is high, such as climbing a hill at high speed or towing a trailer, it's best to use highest RPM possible without redlining the engine. This will result in the thickest oil film. The reason is, when the RPM increases, viscous reaction force applied by the oil increases, as viscous forces are directly proportional to speed (RPM).

Another advantage of thinner oil at high RPMs is that the oil pressure will be lower, which will result in more oil flow as the oil-pressure relief valve opens and the pressure maxes out at a higher flow. This results in more engine cooling because of more oil flow. Bearings will also run cooler, as lower viscosities have less friction. Also, you don't damage your engine seals by high oil pressure caused by high RPM, as lower viscosities will generate less pressure for the most RPM range.

 

[KrisZ]

Originally Posted By: Gokhan
Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.

High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.

If the load is high, such as climbing a hill at high speed or towing a trailer, it's best to use highest RPM possible without redlining the engine. This will result in the thickest oil film. The reason is, when the RPM increases, viscous reaction force applied by the oil increases, as viscous forces are directly proportional to speed (RPM).


All this is great, but you forgot about one thing, oil temperature. With higher RPM the temperature increases greatly even under light load. OP's case is a prime example. High speed, high RPM, so by your theory the thinnest oil possible should suffice since the RPM is high, yet all those bigger German cars, supposedly made for Autobahn, spec thicker oils. Could it be because under prolonged high speeds and RPMs the oil thins out more than at low RPMs? Of course it is.

Also, please tell me what automatic transmission made for the past decade or two will lug the engine? This is the driving dynamic in America, low rpm most of the time with occasional bursts to 3-5k RPM range because that's what the transmissions have been programmed to do. Meanwhile the rest of the world drives stick shifts which varies the driving dynamic greatly.

 

[Gokhan]

Originally Posted By: KrisZ
Originally Posted By: Gokhan
Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.

High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.

If the load is high, such as climbing a hill at high speed or towing a trailer, it's best to use highest RPM possible without redlining the engine. This will result in the thickest oil film. The reason is, when the RPM increases, viscous reaction force applied by the oil increases, as viscous forces are directly proportional to speed (RPM).


All this is great, but you forgot about one thing, oil temperature. With higher RPM the temperature increases greatly even under light load. OP's case is a prime example. High speed, high RPM, so by your theory the thinnest oil possible should suffice since the RPM is high, yet all those bigger German cars, supposedly made for Autobahn, spec thicker oils. Could it be because under prolonged high speeds and RPMs the oil thins out more than at low RPMs? Of course it is.

Also, please tell me what automatic transmission made for the past decade or two will lug the engine? This is the driving dynamic in America, low rpm most of the time with occasional bursts to 3-5k RPM range because that's what the transmissions have been programmed to do. Meanwhile the rest of the world drives stick shifts which varies the driving dynamic greatly.

The thing is that high-RPM conditions usually come with high load, such as rapid acceleration or climbing a hill very fast. Looking at the formula above, high RPM helps but then load negates it, and if the load is high enough, you can still end up reducing the MOFT to a point that metal-to-metal contact starts. In that sense, yes, high-RPM operation can require thicker oil, but only if the load is also high. If you're cruising on the freeway with constant speed, using one gear lower will actually increase your MOFT, even though the RPM is higher. This is assuming that you can downshift without redlining the engine.

The coolant and oil temperatures depend on the engine load and ambient temperature. For a given engine load and ambient temperature, higher RPM will actually result in a cooler engine, therefore cooler oil, because the cooling system will circulate the coolant faster and cooling efficiency will increase. Higher RPM by itself results in a cooler engine. What results in a hotter engine is not the higher RPM but the higher load. Owners' manuals recommend against using the overdrive gear when towing a trailer for more charging and cooling efficiency with higher RPM. Note that this is analogous to the MOFT, where the RPM helps but load hurts.

 

[Trav]

Quote:
Toyota Auris for example, specifies all viscosities between 0W-20 and 20W-50. So, it's not only Prius.



Toyota Auris
1. Wahl Mobil 1 ESP Formula 5W-30
Don't make stuff up to try to make a point.
Quote:
From what I heard, few people drive that fast there anyway, and the typical speed on the left lane is not much different than in the US (about 75 MPH in US when there is no traffic). So, the whole "autobahn" issue only applies if you have a BMW-like car and autobahns in your area actually don't have traffic.


When was the last time you drove in Germany?
I drove there for over 30 years and will drive there again next month when i go home like i do every year.
You heard wrong. There are plenty of opportunities to run WOT in any car not just a BMW. No one drives 75mph.
Around the big cities the autobahn maybe full and running slow at times but it opens up and you can fly.

Please don't tell stories you know nothing about.
Don't dig the hole deeper.

 

[Gokhan]

Originally Posted By: Trav
Quote:
Toyota Auris for example, specifies all viscosities between 0W-20 and 20W-50. So, it's not only Prius.



Toyota Auris
1. Wahl Mobil 1 ESP Formula 5W-30
Don't make stuff up to try to make a point.
Quote:
From what I heard, few people drive that fast there anyway, and the typical speed on the left lane is not much different than in the US (about 75 MPH in US when there is no traffic). So, the whole "autobahn" issue only applies if you have a BMW-like car and autobahns in your area actually don't have traffic.


When was the last time you drove in Germany?
I drove there for over 30 years and will drive there again next month when i go home like i do every year.
You heard wrong. There are plenty of opportunities to run WOT in any car not just a BMW. No one drives 75mph.
Around the big cities the autobahn maybe full and running slow at times but it opens up and you can fly.

Please don't tell stories you know nothing about.
Don't dig the hole deeper.

My nephew in Europe has an Auris and I have seen his owner's manual, carefully going through the oil-recommendation pages. It does specify all viscosities between 0W-20 and 20W-50. Next time I go there, I will make a photocopy for you.

Oil recommendations also depend on what's available in a location. If in Germany they only specify "Wahl Mobil 1 ESP Formula 5W-30" for the Auris, I will take your word for it.

I have never been to Germany and I will also take your word for it on how people drive on autobahns. I am only passing what I heard from Germans I know that there are three lanes and the right-lane is the very slow trucks, the middle lane is the people who drive around 65 MPH, and the left lane is the people who drive very fast.

If you want to drive your car with wide-open throttle frequently, then it's fair enough -- you will benefit from thicker oil, perhaps as thick as xW-40. That's something entirely up to the driver and nowhere in the world people are required to drive wide-open throttle, even on German autobahns. That's why they have three lanes on the autobahns.

 

[Trav]

I am only talking about Germany because the OP drives there sometimes and runs WOT. Specs in other Euro countries will probably be different.
Austria and Switzerland are similar to Germany while Finland specs a lot of 0w30. England, Ireland and the Benelux do use some 20w. Italy is big on 0w40 and 5w40.

Germany has a keep to the right law which means unless you are passing someone you must stay to the right.
The law is somewhat lenient, if the right lane is congested with LKW and buses then you can get away with driving in the middle lane until there is ample space to get into the right lane.
Travel in the middle and left lane when the right lane is free is strictly forbidden and is an offense with fines and license points.

So if there are cars in the middle lane passing trucks and you are going faster then you get into the left lane until you can get into the middle.
No one is forced to run WOT but most do if there is room.
Speed limits on autobahns through cities are low and enforced with speed cameras as is dangerous sections.

Running a tiny Nissan Micra 1.1 or similar WOT is a strain on the little engine at 100 MPH which is its top speed but people run them everyday like that.

 

[OVERKILL]

Originally Posted By: Gokhan

The coolant and oil temperatures depend on the engine load and ambient temperature. For a given engine load and ambient temperature, higher RPM will actually result in a cooler engine, therefore cooler oil, because the cooling system will circulate the coolant faster and cooling efficiency will increase. Higher RPM by itself results in a cooler engine. What results in a hotter engine is not the higher RPM but the higher load. Owners' manuals recommend against using the overdrive gear when towing a trailer for more charging and cooling efficiency with higher RPM. Note that this is analogous to the MOFT, where the RPM helps but load hurts.


With thermostatically controlled cooling systems, I don't see how this is possible. If the cooling system was inadequate perhaps.

The reason many manuals advise against towing in overdrive is due to the lock-up not being capable of handling the load, and the transmission not being strong enough. And of course the constant shifting in/out of O/D if the engine can't pull the weight.

HD trucks have no such advisory because of the transmissions being robust enough to handle the load and are equipped with adequate coolers to deal with the increased heat generated while towing. My Expedition for example does not advise against towing in O/D, and tows just fine in it. It has a dual-clutch converter and can handle full-power up-shifts through all four gears. Any super duty (or equivalent truck) is the same way. It is the lighter duty vehicles who don't have a transmission that was designed to tow that carry these advisories. And even then, towing can (and will) often shorten the life of those transmissions significantly through elevated transmission temps, regardless of the gear you are in. They lack adequate coolers to keep the temperature in check.

But your point about oil temp, MOFT, RPM and load supports exactly what Trav and KrisZ are saying. When you are flying down the Autobahn, especially in a vehicle like the OP's which doesn't have a great deal of power, you will be at high rpm and likely close to 100% load. So you will have elevated oil temperatures, elevated rpm and elevated load. This requires a heavier oil to provide adequate protection.

 

[dave1251]

Originally Posted By: Gokhan
Originally Posted By: KrisZ
Originally Posted By: Gokhan
Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.

High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.

If the load is high, such as climbing a hill at high speed or towing a trailer, it's best to use highest RPM possible without redlining the engine. This will result in the thickest oil film. The reason is, when the RPM increases, viscous reaction force applied by the oil increases, as viscous forces are directly proportional to speed (RPM).


All this is great, but you forgot about one thing, oil temperature. With higher RPM the temperature increases greatly even under light load. OP's case is a prime example. High speed, high RPM, so by your theory the thinnest oil possible should suffice since the RPM is high, yet all those bigger German cars, supposedly made for Autobahn, spec thicker oils. Could it be because under prolonged high speeds and RPMs the oil thins out more than at low RPMs? Of course it is.

Also, please tell me what automatic transmission made for the past decade or two will lug the engine? This is the driving dynamic in America, low rpm most of the time with occasional bursts to 3-5k RPM range because that's what the transmissions have been programmed to do. Meanwhile the rest of the world drives stick shifts which varies the driving dynamic greatly.

The thing is that high-RPM conditions usually come with high load, such as rapid acceleration or climbing a hill very fast. Looking at the formula above, high RPM helps but then load negates it, and if the load is high enough, you can still end up reducing the MOFT to a point that metal-to-metal contact starts. In that sense, yes, high-RPM operation can require thicker oil, but only if the load is also high. If you're cruising on the freeway with constant speed, using one gear lower will actually increase your MOFT, even though the RPM is higher. This is assuming that you can downshift without redlining the engine.

The coolant and oil temperatures depend on the engine load and ambient temperature. For a given engine load and ambient temperature, higher RPM will actually result in a cooler engine, therefore cooler oil, because the cooling system will circulate the coolant faster and cooling efficiency will increase. Higher RPM by itself results in a cooler engine. What results in a hotter engine is not the higher RPM but the higher load. Owners' manuals recommend against using the overdrive gear when towing a trailer for more charging and cooling efficiency with higher RPM. Note that this is analogous to the MOFT, where the RPM helps but load hurts.


Here you go mate this will help you out.


http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729180&page=1

 

[Doug Hillary]

Hi,
OVERK1ll - for interest's sake the following factors typically apply to OTR HD vehicle's engines and drive lines

Engine
1 - Normal
Coolant >96C
Oil >110C

2 - Warning
Coolant 100C
Oil 115C

3 - Powerdown/shutdown
Coolant 106C
Oil 120C

Drive Line
Normal >120
Warning 150C

In the case of engine the powerdown/shutdown process is progressive but quite quick in order to avaoid serious engine damage. Of course "safety margins" apply with these temperatures

In the case of Porsche engines (928 as an example) the progressive nature of thermostat controls (fan speed, coolant flow and oil cooler) ensure all margins fail safe. It is similar in OTR vehicles due to a lot of say 50% engine loading
Under heavy loading and little air flow the system is of course at maximum efficiency

In my experience and in operation the averages against the "normal" figures noted above are:

Engine;
Coolant & Oil 90%

Drive line 80%

Like you indicate a lot depends on the adequacy of the cooling system "package"

 

[Geonerd]

Originally Posted By: Gokhan
Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.


High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.


Agree with the overall goodness of HTHS, but keep in mind that big end journal loads will rise exponentially with RPM. At some point, these rapidly rising loads will unbalance your MOFT equation and the oil film will collapse.

 

[chiks]

A piston moving down is going to create air pressure. How does this qualify as blowby?

 

[TFB1]

Originally Posted By: Gokhan
Originally Posted By: KrisZ
Originally Posted By: Gokhan
Originally Posted By: KrisZ
Also, since most cars are manual, they are revved higher between gear changes even at slow speeds.

High RPMs actually require thinner oil than low RPMs. Read the reference I posted above. In the hydrodynamic-lubrication regime, the minimum oil-film thickness is proportional to the RPM and HTHS viscosity and inversely proportional to the load:

MOFT ~ RPM * (HTHS viscosity) / Load

Therefore, higher the RPM, more the MOFT. The wear happens if the RPM is low when the load is high, which is engine lugging. In these situations, a higher HTHS viscosity helps to insure more MOFT.

If the load is high, such as climbing a hill at high speed or towing a trailer, it's best to use highest RPM possible without redlining the engine. This will result in the thickest oil film. The reason is, when the RPM increases, viscous reaction force applied by the oil increases, as viscous forces are directly proportional to speed (RPM).


All this is great, but you forgot about one thing, oil temperature. With higher RPM the temperature increases greatly even under light load. OP's case is a prime example. High speed, high RPM, so by your theory the thinnest oil possible should suffice since the RPM is high, yet all those bigger German cars, supposedly made for Autobahn, spec thicker oils. Could it be because under prolonged high speeds and RPMs the oil thins out more than at low RPMs? Of course it is.

Also, please tell me what automatic transmission made for the past decade or two will lug the engine? This is the driving dynamic in America, low rpm most of the time with occasional bursts to 3-5k RPM range because that's what the transmissions have been programmed to do. Meanwhile the rest of the world drives stick shifts which varies the driving dynamic greatly.

The thing is that high-RPM conditions usually come with high load, such as rapid acceleration or climbing a hill very fast. Looking at the formula above, high RPM helps but then load negates it, and if the load is high enough, you can still end up reducing the MOFT to a point that metal-to-metal contact starts. In that sense, yes, high-RPM operation can require thicker oil, but only if the load is also high. If you're cruising on the freeway with constant speed, using one gear lower will actually increase your MOFT, even though the RPM is higher. This is assuming that you can downshift without redlining the engine.

The coolant and oil temperatures depend on the engine load and ambient temperature. For a given engine load and ambient temperature, higher RPM will actually result in a cooler engine, therefore cooler oil, because the cooling system will circulate the coolant faster and cooling efficiency will increase. Higher RPM by itself results in a cooler engine. What results in a hotter engine is not the higher RPM but the higher load. Owners' manuals recommend against using the overdrive gear when towing a trailer for more charging and cooling efficiency with higher RPM. Note that this is analogous to the MOFT, where the RPM helps but load hurts.


I'm not going to believe higher RPM would give cooler temps, simply because internal friction(piston ring drag on cyl walls for one) is far greater at say 5000 rpm vs 2000 rpm... Also valve springs will run far hotter as their compressing creates heat... Twenty years ago the NASCAR boys were dropping valves regularly because of broken springs, testing found at 8000 RPM plus(4000 for the valve train) their high pressure springs were running red hot, which led to improved metallurgy in modern springs... Yeah the comeback will be we arn't talking about NASCAR engines, but I'll guarantee you ANY spring is operating at a higher temp at elevated RPMs...

As RPMs increase above 4000 RPM, the oil temps will no doubt rise dramatically in most any engine without a oil cooler...

 

[Gokhan]

Originally Posted By: Trav
I am only talking about Germany because the OP drives there sometimes and runs WOT. Specs in other Euro countries will probably be different.
Austria and Switzerland are similar to Germany while Finland specs a lot of 0w30. England, Ireland and the Benelux do use some 20w. Italy is big on 0w40 and 5w40.

Germany has a keep to the right law which means unless you are passing someone you must stay to the right.
The law is somewhat lenient, if the right lane is congested with LKW and buses then you can get away with driving in the middle lane until there is ample space to get into the right lane.
Travel in the middle and left lane when the right lane is free is strictly forbidden and is an offense with fines and license points.

So if there are cars in the middle lane passing trucks and you are going faster then you get into the left lane until you can get into the middle.
No one is forced to run WOT but most do if there is room.
Speed limits on autobahns through cities are low and enforced with speed cameras as is dangerous sections.

Running a tiny Nissan Micra 1.1 or similar WOT is a strain on the little engine at 100 MPH which is its top speed but people run them everyday like that.

Thanks for the info on the autobahns.

Actually the US interstates are not that much different than the autobahns at all. According to Wikipedia, the average speed on the autobahns in rural areas is 87 MPH. Here we have a 75 MPH speed limit but you don't normally get ticketed unless you exceed the speed limit by 15 MPH or more, therefore effectively our speed limit on the interstates is 89 MPH. A lot of the people on rural interstates stick to the 75 MPH but a lot of them drive in excess of 85 - 90 MPH, some risking getting ticketed. So, things are not much slower here.

Also, in US, it's usually a lot hotter, and we have a lot of deserts in the western part of US. Your oil will run thinner as a result, no matter how powerful your cooling system is, engine fans struggling to keep the coolant temperature not too higher than 95 C, at which the thermostat fully opens.

Probably one of the most demanding drives around here is the I-15 interstate between Los Angeles and Las Vegas. People drive around 85 MPH on long stretches of 10% uphill grades with the outside temperature being 45 C or more. Even some of the powerful cars struggle.

The two differences here are that in rural areas interstates have only two lanes and the keep-right law isn't strictly enforced, leading to some slow drivers impeding the traffic. Very slow trucks (going as slow as 35 MPH) in a truck convoy often get frustrated and try to pass the truck going, say, 34 MPH in front of it, only 1 MPH faster, and imagine how long it takes for a truck to pass another with only 1 MPH speed difference. I drove cross-country on the interstates twice, and both were a lot of fun.

The no-speed-limit on autobahns seems to be as a result of the government policy to help the German auto industry so that the German cars are built and marketed as performance cars and the demand for them around the world is kept high in this way. Regarding actual speeds, US interstates are not that much slower than the autobahns, our actual rural-interstate speeds being not much lower than the autobahns' actual 87 MPH average. You can only speed so much before things start getting dangerous, as the kinetic energy and braking distance increase with the square of the speed. Most sane people won't drive faster than 100 MPH as a result, no matter what car they drive and where. Moreover, since most analog speedometers are designed to show 10% more than the actual speed, when you see 100 MPH (161 km/h) on your speedometer, your actual speed is only 90 MPH (145 km/h).

 

[Trav]

I have driven over 270KMH hitting 310 Kmh on my CBR100XX for over an hour without backing out of the throttle any significant degree, all perfectly legal.
In a decent car with a 3.0 ltr machine 200-220 Kmh is normal cruising speed.

Believe me there is no comparison whatsoever between US highways and German autobahns.

Looks like 87 Mph to me. Add 100 Mph to that. This guy is cruising at over 180 MPH.

 

[Trav]

Quote:
You can only speed so much before things start getting dangerous, as the kinetic energy and braking distance increase with the square of the speed.

Thats true if you cant drive or they hand out driving licenses wholesale like they do here in the US to 16 and 17 yr olds.
Basically you need to be able to aim the car/bike and here you go, you don't actually need to know how to really drive/ride it with any skill.