2015 Skyactiv 0w20 vs 5w30 MPG

[buster]

Haven't noticed much if any of a difference at all in terms of fuel economy. In fact I was telling The Critic the other day I was able to get 41.8 mpg on the 5w30 EP oil, cruising at 80 mph too.

Really impressed with this car and the Skyactive engine. I now have 21,300 miles on it. I still have to send off a UOA of M1 0w20 with 8,000 miles on it from 2 oil changes ago.

I'll probably switch back to 0w20 for the winter, or maybe go with AFE 0w30. The HT/HS difference between the 20 and 30 grade is a small 11%.

 

[badtlc]

I'm having a problem with very mild consumption (about .5-.75 qt per 10k mi OCI). I think after my Mobil 0W20 AFE stash is done (next OCI finishes it off) I think I'm going to run Mobil 1 0W40 for the fun of it.

 

[HTSS_TR]

Your car is still under warranty I would use recommended grade, is it 0W20 ?

 

[JOD]

Originally Posted By: badtlc
I'm having a problem with very mild consumption (about .5-.75 qt per 10k mi OCI). I think after my Mobil 0W20 AFE stash is done (next OCI finishes it off) I think I'm going to run Mobil 1 0W40 for the fun of it.


I'm not sure I'd describe .05-.75 qt over a 10K OCI as a "problem"--even a mild one. I'm sure the 0W40 would do fine, but I wouldn't be surprised if consumption went up a bit. Regardless though, it seems like a great engine.

 

[buster]

.5 to .75 qt per 10k miles is hardly a problem. I don't see any consumption and I drive it aggressively. 80-90 mph.

You can run a 5w30 in these engines despite the call for a 0w20. The same engine in Mexico gets a 5w30. Won't hurt a thing.

 

[kschachn]

Originally Posted By: buster
Haven't noticed much if any of a difference at all in terms of fuel economy. In fact I was telling The Critic the other day I was able to get 41.8 mpg on the 5w30 EP oil, cruising at 80 mph too.


Please don't tell us you were expecting to be able to see a difference.

 

[Vuflanovsky]

Yeah, my guess would be that the alternator in the 3 has a significantly greater impact on MPG than what oil grade you put in it.

 

[buster]

Originally Posted By: kschachn
Originally Posted By: buster
Haven't noticed much if any of a difference at all in terms of fuel economy. In fact I was telling The Critic the other day I was able to get 41.8 mpg on the 5w30 EP oil, cruising at 80 mph too.


Please don't tell us you were expecting to be able to see a difference.


I was, albeit small.

 

[BikeWhisperer]

Originally Posted By: HTSS_TR
Your car is still under warranty I would use recommended grade, is it 0W20 ?


As per the Magnusen-Moss Warranty Act, it would be up to manufacturer to prove that the engine failure was due to the change in oil weight. As long as the oil you use meets the required specifications (like Dexos1 or SN for example) and use a weight appropriate for the conditions the vehicle is running in, you simply aren't going to have a problem.

 

[kschachn]

Originally Posted By: buster
Originally Posted By: kschachn
Please don't tell us you were expecting to be able to see a difference.

I was, albeit small.


Really? I posted a link to an article a while back that described how it was extremely difficult to determine real-world fuel economy, given all the variables in everyday driving. One of the things they found out is that even at the same gas station the fuel can vary in energy density by 4%. That right there pretty much makes any little variation due to oil weight fall into the noise.

It is also a factor that helps all those oil additive companies make claims that can't be disproved by the casual driver. Note that they never offer up lab results on a standardized test engine, only what they call "real world improvements". Good luck measuring that.

Now that doesn't mean there can't be an improvement, otherwise all this research and dev into lighter oils would be for naught. You're just never going to measure it yourself.

 

[pbm]

Originally Posted By: badtlc
I'm having a problem with very mild consumption (about .5-.75 qt per 10k mi OCI). I think after my Mobil 0W20 AFE stash is done (next OCI finishes it off) I think I'm going to run Mobil 1 0W40 for the fun of it.


I wouldn't think twice about running 5w20 or 5w30 in summer but I wouldn't run 0w40 in any season....2 grades above recommendation is too thick for my liking....

 

[buster]

Originally Posted By: kschachn
Originally Posted By: buster
Originally Posted By: kschachn
Please don't tell us you were expecting to be able to see a difference.

I was, albeit small.


Really? I posted a link to an article a while back that described how it was extremely difficult to determine real-world fuel economy, given all the variables in everyday driving. One of the things they found out is that even at the same gas station the fuel can vary in energy density by 4%. That right there pretty much makes any little variation due to oil weight fall into the noise.

It is also a factor that helps all those oil additive companies make claims that can't be disproved by the casual driver. Note that they never offer up lab results on a standardized test engine, only what they call "real world improvements". Good luck measuring that.

Now that doesn't mean there can't be an improvement, otherwise all this research and dev into lighter oils would be for naught. You're just never going to measure it yourself.


I agree. You're right.

 

[JOD]

yeah, measuring feathers on a truck scale, as they say... Measuring FE can be done, but controlling the variables is just way tougher than folks realize. Air density, wind, drafting all play such a huge role when so much energy is going against wind resistance.

I know some folks have used higher octane fuel to ward off fuel dilution, and I've wondered how that effects fuel economy--but again, tough for an individual to quantify. Are you running 87 octane in yours?