Why do SOPUS oils reduce MPG vs Mobil oils?

[LoneRanger]

Okay, I was running Mobil Clean 5000 5W30 in the Forester until this last OC when I balked on buying MC5000's replacement, Mobil Super 5000. I bought Havoline 5W30 SN/GF5 instead. Approx 1 mpg drop on the avg mpg readout ever since with the Forester. 1500 miles on the Havoline so far.

I was running Mobil 1 Turbo-Diesel Truck 5W40 in the wife's Volkswagen TDI (diesel). There was a sale on Shell Rotella T6 synthetic 5W40 gallon jugs. Used that for the last OC on the TDI. About a 2 mpg drop (computed by hand, car not equipped w/ avg mpg readout). 8000 miles on the Rotella T6 so far.

Coincidence that with each car its an approximate 4% drop? Ready to use Mobil again in both vehicles next OC!

 

[glum]

Well this is BITOG so ... if any MPG calculation implicates SOPUS products, it is faulty (out of hand). However if someone claims 147 MPG in a poorly-tuned V8 Chevy Impala driving into a strong headwind uphill, it's true (unless they were using Royal Purple).

 

[LoneRanger]

FWIW, the Ford Escape gets dealership service dept. OC's and thus Motorcraft bulk 5W20 syn-blend (I guess). Don't track the MPG on it-- son's college rig.

 

[LoneRanger]

Honestly got nothing against SOPUS products, both cars run smooth and quiet on the two mentioned SOPUS oils, I'm just anal about fuel economy and noticed this trend since the OC's. I have noticed slightly less valvetrain noise from the Subaru with the Havoline than when it was on MC5000... very slight but I'm quite tuned in to my ride's behavior and noticed slightly less noise. The TDI is a clatter-fest no matter whats in the crankcase.

Originally Posted By: glum
Well this is BITOG so ... if any MPG calculation implicates SOPUS products, it is faulty (out of hand). However if someone claims 147 MPG in a poorly-tuned V8 Chevy Impala driving into a strong headwind uphill, it's true (unless they were using Royal Purple).

 

[Eddie]

Much depends on the weather. Gas is changed depending on expected weather.

 

[friendly_jacek]

Is there a difference in viscosity?

 

[simple_gifts]

I wore a blue shirt one day; I got 1 mpg less.

 

[fdcg27]

I've only used SOPUS products in our Forester for a run from 4K to 9K on QTP 10W-30, so I really can't comment on any loss of fuel economy in that application.
Fuel economy in the Forester is lousy with any oil or fuel.
Both of the Accords have had many miles on both M1 and PP, and I really can't see any systematic difference in fuel economy between the two brands of oil.
I don't think that the loss in fuel economy you've measured has anything to do with the brand of oil used.
Finally, Havoline is not a SOPUS brand, and is usually blended at the thin end of each grade, so it should be a fairly economical oil, and while T6 is a SOPUS product, it is certainly no thicker than M1 5W-40 TDT.
I have used and will use either.
I've also used Havoline, and thought it was perfectly good.
Still, if XOM floats your boat, use it.

 

[LoneRanger]

Originally Posted By: fdcg27
and while T6 is a SOPUS product, it is certainly no thicker than M1 5W-40 TDT.


Yes it is. And, if 25 - 26 mpg around town is lousy, then my Forester gets lousy mpg too. 25 on havoline, 26 on Mobil. In town. Highway add about 3 to each figure.

 

[daves87rs]

Originally Posted By: simple_gifts
I wore a blue shirt one day; I got 1 mpg less.




Yep.

Guess someone forgot the change in add pack....

 

[Finklejag]

Havoline = Chevron

Rotella T6 viscosity

40°C 87
100°C 14.2

Mobil 1 TDT viscosity

40°C 97.9
100°C 14.5


So the Mobil 1 TDT is thicker then T6.

 

[OldCowboy]

Yep, you've blamed SOPUS for something that isn't their fault.

 

[FZ1]

I believe it. Look,your facts are your facts,despite what the "experts",say. The oil you run can make a difference. I went from dealer fill to synthetic and got about 1-1.5 mpg more. I run only synthetic,now. I think it pays for itself with fractionally higher mpg.

 

[Towncivilian]

The real secret to MPG improvement is changing out the blinker fluid every 23.78012 thousand miles on the dot.

 

[chet2]

i noticed a difference on M1 0-20 in a ford focus, mustve been close to 38mpg w/ 5 speed...mobil super is just as good as pz for less $$$

 

[chevrofreak]

Originally Posted By: Finklejag
Havoline = Chevron

Rotella T6 viscosity

40°C 87
100°C 14.2

Mobil 1 TDT viscosity

40°C 97.9
100°C 14.5


So the Mobil 1 TDT is thicker then T6.


TDT has a significantly lower VI than T6. No thanks.

 

[fdcg27]

Originally Posted By: LoneRanger
Originally Posted By: fdcg27
and while T6 is a SOPUS product, it is certainly no thicker than M1 5W-40 TDT.


Yes it is. And, if 25 - 26 mpg around town is lousy, then my Forester gets lousy mpg too. 25 on havoline, 26 on Mobil. In town. Highway add about 3 to each figure.



As others have pointed out above, T6 is not as thick as TDT.
Our Forester is an automatic, and averages about 1 mpg less than yours, which I do consider lousy for a four cylinder car with no real power. OTOH, it is not particularly light and AWD does not exactly enhance fuel economy, although it's magic when you really need it.
Real world fuel economy is about what I expected from the car when we bought it, so I'm not complaining, just stating a fact.

 

[demarpaint]

Remember this is Bitog and when we talk about better mpg it is usually brought up that the average person is not capable of accurately calculating mpg, too many variables. So odds are it is nothing more than a coincidence, a change in driving habits, or a good tail wind. When someone claims they saw a gain in mpg changing from a 5W30 to a 5W20, or using a UCL and sees an improvement, they are quickly taken to the woodshed. Same goes here, LOL.

 

[LoneRanger]

That's it then... I'm switching to Royal Purple! Yeah, that's the ticket.

 

[Garak]

Originally Posted By: simple_gifts
I wore a blue shirt one day; I got 1 mpg less.


Agreed. Unless we're comparing using 20w-50 in a 5w-20 or 0w-20 application, I think we're really splitting hairs here. It's hard enough to compare fuel economy on two very close viscosities, let alone one viscosity over two brands.

There are simply too many variables. I track my fuel economy all the time. That's for my tax records and has a benefit for me to keep an eye on my driving habits and to see if something goes seriously out of tune in the vehicle.

I went on a long two way trip one day. I went the same speed coming and going. I got about 20 mpg going, and 34 mpg returning. A 50 mph wind the switches from a headwind to a tailwind makes a big difference.

Fuel quality, fuel fill level, temperature, humidity, tire pressure, oil viscosity, driving style, vehicle loading, terrain.... Too many variables.

I would suggest we have enough trouble filling our vehicles to within a couple percent of every other fill up, let alone appropriately accounting for the other variables. The error bars alone are greater than 1 mpg for just about every vehicle out there.