I AmTired of Everybody Saying that Every Driving Situation is Severe.
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I guess it depends on the state.
From http://www.baconsrebellion.com/Issues04/01-05/Curious.htm :
"At the end of 2002 Virginia had 47,582 miles of secondary roads, of which 9,474 were untreated and 138 were unsurfaced."
In fact:
"According to our VDOT source, the agency no longer accepts maintenance responsibility for additional miles of unpaved roads, except those that are planned for immediate hard surfacing under a special rural addition program."
(All secondary and primary roads in Virginia are maintained by VDOT except those in incorporated cities, which are maintained by the city. Virginia has very few incorporated cities).
From http://www.baconsrebellion.com/Issues04/01-05/Curious.htm :
"At the end of 2002 Virginia had 47,582 miles of secondary roads, of which 9,474 were untreated and 138 were unsurfaced."
In fact:
"According to our VDOT source, the agency no longer accepts maintenance responsibility for additional miles of unpaved roads, except those that are planned for immediate hard surfacing under a special rural addition program."
(All secondary and primary roads in Virginia are maintained by VDOT except those in incorporated cities, which are maintained by the city. Virginia has very few incorporated cities).
JohnnyLock: No disrespect taken. You are correct, most goes out of the exhaust, but if the car never reaches maximum temps, some does stay in the engine as G-Mann II has stated. You will really notice it up North in the winter months watching all the condensation coming out of car exhaust. And it's not just cars, your lawn mover does the same thing, but you don't realize it because it's always running at peak rpm to cut your grass.
Just two quick things that we have all experienced at one time or another. Ever taken off the oil cap and it was full of white milky gue. That's condensation. Ever got ready to take a trip from lets say Houston to Austin. Checked your oil before you left and it was full. Checked it when you returned home and it was an 1/8 of a quart low. The trip burned off the excess water in the system. When you mix the water with the by products of burning fuel you get acids in the oil. That's why we have to change it. In reality the gasoline engine is just one big nasty pump. Sucks in cold air, builds a fire, makes acids, and blows it out the exhaust. Over the years it's been getting better with better oils, fuel injection, catalyst, etc., but we still have a long way to go.
I read a report last year that said if gasoline was invented today, it would be outlawed as hazardous material.
Just two quick things that we have all experienced at one time or another. Ever taken off the oil cap and it was full of white milky gue. That's condensation. Ever got ready to take a trip from lets say Houston to Austin. Checked your oil before you left and it was full. Checked it when you returned home and it was an 1/8 of a quart low. The trip burned off the excess water in the system. When you mix the water with the by products of burning fuel you get acids in the oil. That's why we have to change it. In reality the gasoline engine is just one big nasty pump. Sucks in cold air, builds a fire, makes acids, and blows it out the exhaust. Over the years it's been getting better with better oils, fuel injection, catalyst, etc., but we still have a long way to go.
I read a report last year that said if gasoline was invented today, it would be outlawed as hazardous material.
Much of last year my wife had a job where she was driving 30 miles each way 5 days a week on mostly rural, 2 lane roads posted at 55. I stayed with the 3 month intervals although several of them stretched 6-7K on dino. I felt that the conditions no longer met the requirements for severe duty and 3K.
Gasoline is hazardous? How many people die every year from the direct or indirect effects of water? If you think I am all wet, go jump in the lake.
Gasoline is hazardous? How many people die every year from the direct or indirect effects of water? If you think I am all wet, go jump in the lake.
"According to the Motor & Equipment Manufacturers Association 80 percent of driving is severe. It is easy to appreciate this in the trucking industry but less obvious in the use of everyday automobiles."
Per data from an older site it appears that in urban areas trip length is pretty short, and since most people in the US live in urban areas I'll guess most cars meet the severe duty cycle:
http://www.fypower.org/save_gasoline/action/tip_details.html?tar=3&hdr=6
6. Offer safe bicycle storage; arrange safe bicycling instruction.
What Is the Issue? National transportation surveys indicate that more than half the auto trips in the United States are less than two miles long. A 1996 Air Resources Board study of Southern Californians' driving habits found that drivers took an average of seven trips a day. The average trip length was 7.6 miles, and more than 31% of the trips were one mile or less. That means about two of those seven trips were within a very easy and short bicycle ride, which would save gasoline and provide exercise.
Per data from an older site it appears that in urban areas trip length is pretty short, and since most people in the US live in urban areas I'll guess most cars meet the severe duty cycle:
http://www.fypower.org/save_gasoline/action/tip_details.html?tar=3&hdr=6
6. Offer safe bicycle storage; arrange safe bicycling instruction.
What Is the Issue? National transportation surveys indicate that more than half the auto trips in the United States are less than two miles long. A 1996 Air Resources Board study of Southern Californians' driving habits found that drivers took an average of seven trips a day. The average trip length was 7.6 miles, and more than 31% of the trips were one mile or less. That means about two of those seven trips were within a very easy and short bicycle ride, which would save gasoline and provide exercise.
Buster: You are home free my friend
So, if somebody 1) drives on a dusty road everyday to and from his house; 2) has to take 7 mile trips into and out of town; 3) averages under 30 MPH; and 4) burns up 200 gallons of gas every 3K miles, does this qualify as severe servcice?
Sorry for the rant, but some of us really do have "severe" driving conditions....
Bob W.
It's all relative. With the exception of dusty conditions, the severity of the conditions are variable. How long is that dirt road you live on? The GM OLM does a great job of showing that.
Even dusty is variable. How long IS that dirt road you live on. Only problem there is, unless you do UOAs, you really have no way of teling how severe it is...
Even dusty is variable. How long IS that dirt road you live on. Only problem there is, unless you do UOAs, you really have no way of teling how severe it is...
I live in rural Vacaville, and the road leading up to the house is about 1/2 mile, claims to be chip sealed but is in pretty crummy condition, so in the summer especially it is really dusty. The potholes are beating up the wife's Honda pretty good.
I was trying to be humorous about the whole severe driving thing, and hoping to make the point that we cannot always equate our situations with others on the board.
Bob W.
Seeing how most automanufactures are nice enough to tell you what they consider sever it is easy enough to look in your owners manual! I deal with durt roads, short trips under 20 miles are common, salt dureing the winter, towing heavy loads near vechiles gross load capacity every time the wife goes to see her mom with the kids etc...... Now if I was driveing a Ferari I would not live near a dirt road let alone drive down one and I would not be exposeing it to the chemicaly treated salt Michigan likes to throw out all winter long and I would probably not use my Ferari to run to the store 7 miles away for a loaf of bread! I would imagine I would tend to drive it in a spirited fashion on two lane rural hwy's with lots of curves and few pedastrains.
So my point are that each person can decide for themselfs based on Owners Manual and their environment!If someone cannot decide for themselfs what catagory they belong in then they need to let someone do it for them!
So my point are that each person can decide for themselfs based on Owners Manual and their environment!If someone cannot decide for themselfs what catagory they belong in then they need to let someone do it for them!
Well - I actually like changing the oil to some degree. Oil changes are almost a ritual. Disposal of oil is easy, as my city has a recycling center with a large used oil collection tank.
Now I don't necessarily subscribe to the 3000 mile oil change interval, but getting down and dirty by changing the oil myself makes me feel as if I'm doing something. Doing it more often than absolutely necessary makes me feel better about how I'm treating my vehicles. The cost isn't that much, and is less than many other "hobbies". In the end, 5 quarts of Mobil 1 5W-30 three times a year doesn't break the bank. Heck - people here are obsessing over finding the "green elixer" or stressing about specials at AutoZone.
Taking it to a quickie lube (or any other shop) wouldn't be the same. They wouldn't wait 20 minutes for the oil flow to slow down to little drips. They wouldn't take extra care to route the oil from the filter removal away from the axle. They won't use a torque wrench to tighten the drain bolt to 33 ft-lbs (only for my WRX).
Now I don't necessarily subscribe to the 3000 mile oil change interval, but getting down and dirty by changing the oil myself makes me feel as if I'm doing something. Doing it more often than absolutely necessary makes me feel better about how I'm treating my vehicles. The cost isn't that much, and is less than many other "hobbies". In the end, 5 quarts of Mobil 1 5W-30 three times a year doesn't break the bank. Heck - people here are obsessing over finding the "green elixer" or stressing about specials at AutoZone.
Taking it to a quickie lube (or any other shop) wouldn't be the same. They wouldn't wait 20 minutes for the oil flow to slow down to little drips. They wouldn't take extra care to route the oil from the filter removal away from the axle. They won't use a torque wrench to tighten the drain bolt to 33 ft-lbs (only for my WRX).
June in Alberta results in daytime highs around 20?c. Condensation coming out the exhaust is the norm here for most cars at start up. Many car manuals and "experts" say if you live Canada, than you live in a severe environment. Is this true?
Also if you owned a Ferrari you might be able to spell Ferrari (to say nothing of the other ten words...
Hi,
this MAY be a severe case;
In the 1960's I used a small fleet of SWB petrol engined Landrovers to access mountain top Pylon construction sites in the Fiordland district of NZ
The working height was up to 5800' and this was travelled about 5000' up and down daily - 30kms in each direction. The road surfaces ranged from deep mud, rocks etc. to dusty gravel. The maximum gradient was 18%. The ambient range was -20C to 25C.
The little 'Rovers (OHI/SE engines)towed fuel supply trailers, compressors, loader bucket trailers and etc and were always driven hard and mostly laden too
Was this severe service? Well we just used the maker's normal OCI (and HD oils) and in 18months we never lost an engine via wear or with an oil related issue! Air cleaners (oil bath type) etc were looked after with care as were carbs, ignition etc (engine tuning)
It is mostly always a case of common sense tempered with a dose of reality
Regards
Doug
this MAY be a severe case;
In the 1960's I used a small fleet of SWB petrol engined Landrovers to access mountain top Pylon construction sites in the Fiordland district of NZ
The working height was up to 5800' and this was travelled about 5000' up and down daily - 30kms in each direction. The road surfaces ranged from deep mud, rocks etc. to dusty gravel. The maximum gradient was 18%. The ambient range was -20C to 25C.
The little 'Rovers (OHI/SE engines)towed fuel supply trailers, compressors, loader bucket trailers and etc and were always driven hard and mostly laden too
Was this severe service? Well we just used the maker's normal OCI (and HD oils) and in 18months we never lost an engine via wear or with an oil related issue! Air cleaners (oil bath type) etc were looked after with care as were carbs, ignition etc (engine tuning)
It is mostly always a case of common sense tempered with a dose of reality
Regards
Doug
I say if you don't get a chance to truly warm up your oil before you drive non-stop at 75mph or less for at least 30 miles in non-dusty conditions at temps above 40ºF, you might have a case for severe driving conditions. While I think we may not give enough credit to the capabilities of modern oils to cope with severe conditions, I also think we might be dismissing what consitutes severe conditions too readily as well.
[ June 02, 2005, 11:11 PM: Message edited by: pscholte ]
[ June 02, 2005, 11:11 PM: Message edited by: pscholte ]
JHZR2
Staff member
The way I look at it is this:
Very short trips, i.e. car rarely gets up to temperature: 3000 mi OCI on dino, and based upon my tests, 5000 mi on M1, but watch closely for bad wear numbers.
Stop and go is a tough one. Here is the way I see it. If you do many miles of stop and go, your engine and oil WILL get up to temperature. Condensation is not an issue at that point, and the oil will stay dry. This is actually half decent use for oil, as the engine temperatures will be relatively low (fan and radiative cooling levels are high), and since the engine only needs minimal power to keep going (say, 15 kW), then at 30% efficiency, only about 30 kW needs to be dissipated. This equals less thermal load to the oil, and thus lower oil temperatures, while still in the regime that allows for boiling off of condensate. The generally lower thermal load will reduce chance of sludging, but will likely increase chances of fuel dilution. The fact of lower thermal may be reduced somewhat by lower flowrates through the front of the vehicle. 5000 mi OCIs are easy doing this kind of driving, and may be longer.
Easy highway driving (40-70) is the best of all, as it doesnt require much power (maybe 45 kW max, thus the max heat dissipation os only around 100 kWt). there is a lot of flow-based cooling from air passing through the vehicle. All in all, there is good cooling, and not too much power being produced. 10000+ mile OCIs are fine with this driving. Some cars can go to nearly 20k mile OCIs.
Hard highway driving (>70 or lots of jackrabbit, high RPM, etc). This isnt the worst there could be, but as drag increases, the power requirement is higher and higher, potentially exponentially in this regime. Whereas maybe 45 kW was necessary at 65, 100 kW would be necessary at 85 mph. This means that instead of 100 kWt needing to be dissipated, 200 kWt is. the oil will therefore have more thermal duty, and as a result, especially low quality oils will break down quickly. Back to 5000 for this regime, possibly lower.
All in all it is a function of very few things: How hard you drive your car, how hot the bulk temperature of the oil is, and what speeds you drive at. Optimally, we'd drive lightly, the bulk temperature would be just over boiling, and speeds would be maintained where drag isnt a HUGE parasitic, i.e. more realistic speeds. Depending on the degree of departure from these optima, we can determine how much shorter our OCIs must be. Its a complex function due to factors like water, sludge, etc.
UOA is still the best way to determine suitability of your oil/OCI for your driving of a particular type of engine and vehicle.
JMH
Very short trips, i.e. car rarely gets up to temperature: 3000 mi OCI on dino, and based upon my tests, 5000 mi on M1, but watch closely for bad wear numbers.
Stop and go is a tough one. Here is the way I see it. If you do many miles of stop and go, your engine and oil WILL get up to temperature. Condensation is not an issue at that point, and the oil will stay dry. This is actually half decent use for oil, as the engine temperatures will be relatively low (fan and radiative cooling levels are high), and since the engine only needs minimal power to keep going (say, 15 kW), then at 30% efficiency, only about 30 kW needs to be dissipated. This equals less thermal load to the oil, and thus lower oil temperatures, while still in the regime that allows for boiling off of condensate. The generally lower thermal load will reduce chance of sludging, but will likely increase chances of fuel dilution. The fact of lower thermal may be reduced somewhat by lower flowrates through the front of the vehicle. 5000 mi OCIs are easy doing this kind of driving, and may be longer.
Easy highway driving (40-70) is the best of all, as it doesnt require much power (maybe 45 kW max, thus the max heat dissipation os only around 100 kWt). there is a lot of flow-based cooling from air passing through the vehicle. All in all, there is good cooling, and not too much power being produced. 10000+ mile OCIs are fine with this driving. Some cars can go to nearly 20k mile OCIs.
Hard highway driving (>70 or lots of jackrabbit, high RPM, etc). This isnt the worst there could be, but as drag increases, the power requirement is higher and higher, potentially exponentially in this regime. Whereas maybe 45 kW was necessary at 65, 100 kW would be necessary at 85 mph. This means that instead of 100 kWt needing to be dissipated, 200 kWt is. the oil will therefore have more thermal duty, and as a result, especially low quality oils will break down quickly. Back to 5000 for this regime, possibly lower.
All in all it is a function of very few things: How hard you drive your car, how hot the bulk temperature of the oil is, and what speeds you drive at. Optimally, we'd drive lightly, the bulk temperature would be just over boiling, and speeds would be maintained where drag isnt a HUGE parasitic, i.e. more realistic speeds. Depending on the degree of departure from these optima, we can determine how much shorter our OCIs must be. Its a complex function due to factors like water, sludge, etc.
UOA is still the best way to determine suitability of your oil/OCI for your driving of a particular type of engine and vehicle.
JMH
Patman
Staff member
FWIW, I do tons of stop and go driving, with lots of idling due to bad rush hour here. And I saw some very cold temps (below 0F a few times) last winter too. But yet when I got back my UOA, which was a 6100 mile run, the wear numbers were very low, and the TBN was still strong. The key for me is that when I start the car, it gets driven for a long time, and the oil is always up above 180F for at least 20-30min or more. My commute to work takes 45-60min each way, depending on traffic.
So even though it's cold here in the winter, my driving doesn't fit into the severe category, not according to my UOA results. Even when I do a ton of full throttle action during my intervals, it doesn't seem to hurt the engine wear numbers. Another key is that I drive very gently when the oil is under 100F, I try to stay below 1500rpm during this time. Then I limit my rpm to 2000 until the oil is above 150F, and I try not to go full throttle unless it's above 180F (occasionally at the drag strip I've made runs with the oil starting out at 150F though, sometimes you have no choice when you're waiting in the staging lanes too long)
So even though it's cold here in the winter, my driving doesn't fit into the severe category, not according to my UOA results. Even when I do a ton of full throttle action during my intervals, it doesn't seem to hurt the engine wear numbers. Another key is that I drive very gently when the oil is under 100F, I try to stay below 1500rpm during this time. Then I limit my rpm to 2000 until the oil is above 150F, and I try not to go full throttle unless it's above 180F (occasionally at the drag strip I've made runs with the oil starting out at 150F though, sometimes you have no choice when you're waiting in the staging lanes too long)
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