Rotella T6

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Originally Posted By: ccap41
Alright noob question here.. so please be nice

Why use an oil designed to be run in diesel engines?

I'm asking because I too have an EcoBoost engine(2.0) and would like to know for my own engine's sake.

I guess while I'm at it with the noob questions I'll ask what does HTHS standfor/mean? I read it all the time and I have no clue what it means.


Hths stands for high temp high shear, it's a parameter measured that determines the viscosity of an oil at a very high temp. The higher the hths the thicker the oil will be at extreme temperatures. Diesel oils have higher hths than regular Pcmo's because most have turbo's and create a ton of heat. Diesel oils also have very higher detergent and certain anti wear additives such as zinc and phosphorus. That being said for your ecoboost I wouldn't recommend it just like this guys f150.
 
Originally Posted By: HerrStig
Originally Posted By: Fasttimez
Originally Posted By: badtlc
Don't go cheap. Run premium gas. That is the first step in battling fuel dilution.

I've only ever used 93 octane since I bought it.
Paying for 93 doesn't sound real "Eco" to me.


How so? If the EB gets better fuel economy on 93 because it can run more spark advance, that sounds pretty "Eco" to me.

Or perhaps you meant "Eco-nomical" instead of "Eco-logical"? It might be about equal if you run regular gas but get worse gas mileage versus premium gas and get better gas mileage.
 
Last edited:
Well stated sir
smile.gif

Running a diesel\gas oil can be done.. Key factor I believe is what your car specifications are. My car is specd for API SM rated oil. There are actually a number of dual purpose oils out there. Question I have is that if someone's car is specified to run on a API SN oil could or would it be OK to run a dual purpose oil if it was rated SM ? Outside of warranty period of course??
smile.gif
 
Originally Posted By: Gearhead1194
Originally Posted By: ccap41
Alright noob question here.. so please be nice

Why use an oil designed to be run in diesel engines?

I'm asking because I too have an EcoBoost engine(2.0) and would like to know for my own engine's sake.

I guess while I'm at it with the noob questions I'll ask what does HTHS standfor/mean? I read it all the time and I have no clue what it means.


Hths stands for high temp high shear, it's a parameter measured that determines the viscosity of an oil at a very high temp. The higher the hths the thicker the oil will be at extreme temperatures. Diesel oils have higher hths than regular Pcmo's because most have turbo's and create a ton of heat. Diesel oils also have very higher detergent and certain anti wear additives such as zinc and phosphorus. That being said for your ecoboost I wouldn't recommend it just like this guys f150.


Thank you! Much appreciated.

So, in general.. a higher HTHS # would be better as it will shear down less..correct? Or more resistant to shearing?
 
If you plan on short tripping or running long OCI, go for it, turbo diesel oils are particulary good for this since diesel engines pollutes their oil more.
 
Originally Posted By: ccap41
Originally Posted By: Gearhead1194
Originally Posted By: ccap41
Alright noob question here.. so please be nice

Why use an oil designed to be run in diesel engines?

I'm asking because I too have an EcoBoost engine(2.0) and would like to know for my own engine's sake.

I guess while I'm at it with the noob questions I'll ask what does HTHS standfor/mean? I read it all the time and I have no clue what it means.


Hths stands for high temp high shear, it's a parameter measured that determines the viscosity of an oil at a very high temp. The higher the hths the thicker the oil will be at extreme temperatures. Diesel oils have higher hths than regular Pcmo's because most have turbo's and create a ton of heat. Diesel oils also have very higher detergent and certain anti wear additives such as zinc and phosphorus. That being said for your ecoboost I wouldn't recommend it just like this guys f150.


Thank you! Much appreciated.

So, in general.. a higher HTHS # would be better as it will shear down less..correct? Or more resistant to shearing?


The high HTHS number means that the oil will form a thicker film to separate moving surfaces in your engine. Crankshaft to bearing, piston skirt to cylinder wall, etc. But long-term viscosity loss due to shear is a different issue, roughly related to the spread between the low and high temperature numbers of a multigrade oil. In general a lower spread between the W number and the high temperature number, the less an oil will shear over time, meaning more stable protection over an oil change interval.
 
Originally Posted By: A_Harman
Originally Posted By: HerrStig
Originally Posted By: Fasttimez
Originally Posted By: badtlc
Don't go cheap. Run premium gas. That is the first step in battling fuel dilution.

I've only ever used 93 octane since I bought it.
Paying for 93 doesn't sound real "Eco" to me.


How so? If the EB gets better fuel economy on 93 because it can run more spark advance, that sounds pretty "Eco" to me.

Or perhaps you meant "Eco-nomical" instead of "Eco-logical"? It might be about equal if you run regular gas but get worse gas mileage versus premium gas and get better gas mileage.

You will almost never get better fuel mileage with premium high octane gas over regular, because your engine operates at a higher temperature when it's burning high octane gas. Test it in any car/truck and you will see that you get better Fuel mileage with regular low octane gas.
 
Originally Posted By: Hessam
You will almost never get better fuel mileage with premium high octane gas over regular, because your engine operates at a higher temperature when it's burning high octane gas. Test it in any car/truck and you will see that you get better Fuel mileage with regular low octane gas.


You need to spend more time on BITOG learning.

High octane gas doesn't burn hotter. It resists self ignition better than low octane, that's all.

Some high octane has a lower energy density, which will get less energy (miles) per tank, however the increased octane rating means that more boost/spark advance can be used which increases mileage.

My old 4Runner would do more miles per tank on premium, many more, enough to justify the cost.
 
Originally Posted By: Snoman002
1mpg improvement in my g8 when using premium.
Your knock sensors allowed a slight timing advance. Higher octane does not "detonate' as easily which is what the knock sensors are there to detect. As engines age and carbon builds up inside the combustion chambers , RAISING the compression ratio slightly, a bit more octane may deliver some payback, IF the engine has computer controlled timing. IF not, it's throwing money away.
 
Originally Posted By: Fasttimez
Originally Posted By: HerrStig
Originally Posted By: Fasttimez
Originally Posted By: badtlc
Don't go cheap. Run premium gas. That is the first step in battling fuel dilution.

I've only ever used 93 octane since I bought it.
Paying for 93 doesn't sound real "Eco" to me.

It cost me only $12 more per fill up to use 93 vs 87....I'm not that broke.
"A fool and his money".
 
Originally Posted By: A_Harman
Originally Posted By: HerrStig
Originally Posted By: Fasttimez
Originally Posted By: badtlc
Don't go cheap. Run premium gas. That is the first step in battling fuel dilution.

I've only ever used 93 octane since I bought it.
Paying for 93 doesn't sound real "Eco" to me.


How so? If the EB gets better fuel economy on 93 because it can run more spark advance, that sounds pretty "Eco" to me.

Or perhaps you meant "Eco-nomical" instead of "Eco-logical"? It might be about equal if you run regular gas but get worse gas mileage versus premium gas and get better gas mileage.
Hereabouts "93" is about 80 cents higher than 87, the price of which is used to draw the customers into the station.
Payback in extra miles has to be substantial at that price.
 
I don't argue your premise, however, on an '11 Honda CR-V I had, that vehicle consistently turned in a three MPG improvement when using Shell V-Power. Only that vehicle, only that fuel. I wrote about it here in the past.

There is also another reason other than octane rating to run premium fuel. Sometimes buying premium is the only way to get ethanol free. Also, using Shell as an example, contain added/more/better fuel additive. They are promoting that very thing now.

In true BITOG fashion, if one is looking for the "best" fuel, some premium choices in fuel are the only way to go. Maybe not a good ROI but not necessarily throwing money away either. Absolutely no difference between the "premium oil" wars that take place here hourly.

Originally Posted By: HerrStig
Originally Posted By: Snoman002
1mpg improvement in my g8 when using premium.
Your knock sensors allowed a slight timing advance. Higher octane does not "detonate' as easily which is what the knock sensors are there to detect. As engines age and carbon builds up inside the combustion chambers , RAISING the compression ratio slightly, a bit more octane may deliver some payback, IF the engine has computer controlled timing. IF not, it's throwing money away.
 
Originally Posted By: Shannow
High octane gas doesn't burn hotter. It resists self ignition better than low octane, that's all.

Some high octane has a lower energy density, which will get less energy (miles) per tank, however the increased octane rating means that more boost/spark advance can be used which increases mileage.

True! Then do we need to change the setting of this "boost/spark advance" from the original factory engine setting, to achieve this benefit of high octane gas ?
 
Originally Posted By: Shannow
Originally Posted By: Hessam
You will almost never get better fuel mileage with premium high octane gas over regular, because your engine operates at a higher temperature when it's burning high octane gas. Test it in any car/truck and you will see that you get better Fuel mileage with regular low octane gas.


You need to spend more time on BITOG learning.

High octane gas doesn't burn hotter. It resists self ignition better than low octane, that's all.

Some high octane has a lower energy density, which will get less energy (miles) per tank, however the increased octane rating means that more boost/spark advance can be used which increases mileage.

My old 4Runner would do more miles per tank on premium, many more, enough to justify the cost.


I wasn't trying to start a big debate, but I didn't say that premium gas burns hotter... what I said is that your engine operating temperature is higher when running premium gas. those are 2 different things. Your engine is able to create more power when running high octane gas, and engines that create more power operate at a higher temperature. The engine will create less power on regular gas, but for that same reason it also runs cooler when it's burning regular gas. Cooler engines are more efficient (all other things being equal). In modern cars the computer will compensate for timing/ignition, when you switch between different octane gasoline, so the MPG difference most people think they perceive with premium gas, almost always has to do with other factors (weather, tire pressure, A/C on or off, driving style, cargo being carried, city vs. highway driving, etc...)

Consumer Reports had this as one of their common gas-saving myths:
http://www.csmonitor.com/Business/In-Gea...gas-saving-tips

In any case I was told this by my auto mechanics professor at NOVA community college.
 
You argument was that running a higher octane almost never results in an increase in fuel economy. The point remains, many cars do get increased fuel economy by running a higher octane.
 
Originally Posted By: Hessam
Originally Posted By: Shannow
Originally Posted By: Hessam
You will almost never get better fuel mileage with premium high octane gas over regular, because your engine operates at a higher temperature when it's burning high octane gas. Test it in any car/truck and you will see that you get better Fuel mileage with regular low octane gas.


You need to spend more time on BITOG learning.

High octane gas doesn't burn hotter. It resists self ignition better than low octane, that's all.

Some high octane has a lower energy density, which will get less energy (miles) per tank, however the increased octane rating means that more boost/spark advance can be used which increases mileage.

My old 4Runner would do more miles per tank on premium, many more, enough to justify the cost.


I wasn't trying to start a big debate, but I didn't say that premium gas burns hotter... what I said is that your engine operating temperature is higher when running premium gas. those are 2 different things. Your engine is able to create more power when running high octane gas, and engines that create more power operate at a higher temperature. The engine will create less power on regular gas, but for that same reason it also runs cooler when it's burning regular gas. Cooler engines are more efficient (all other things being equal). In modern cars the computer will compensate for timing/ignition, when you switch between different octane gasoline, so the MPG difference most people think they perceive with premium gas, almost always has to do with other factors (weather, tire pressure, A/C on or off, driving style, cargo being carried, city vs. highway driving, etc...)

Consumer Reports had this as one of their common gas-saving myths:
http://www.csmonitor.com/Business/In-Gea...gas-saving-tips

In any case I was told this by my auto mechanics professor at NOVA community college.


Amazing what you can learn outside of bitog!

I understood your point the first time btw.

One of my owner's manuals says it's a waste to use anything more than regular octane. I wonder if that would change if there are carbon deposits that haven't been removed by top tier fuel and fuel system cleaners.
 
Originally Posted By: Hessam
In any case I was told this by my auto mechanics professor at NOVA community college.

In a car that wasn't designed to run premium, that would almost certainly be true. But, if a car is specified to run premium, and you choose to run regular, you are almost certainly to get poorer mileage.
 
Agreed, or worse (perhaps?).

I have owners manuals that say it's ok to run regular instead of premium but that performance and economy will be impacted.

And other owners manuals that say regular octane is verboten.
 
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