5w vs 0w & MPG claims

[heathenbrewing]

I never understood the "higher MPG claim" that 0w30 make, saying improved mileage over 5w30. At operating temps, they are both a 30 weight and that is where a very large percentage of the average drivers time is spent, at operating temps. Sure, startups are easier with a 0w, and those initial few minutes could result in better MPG, but for someone like me who lives in San Diego, my car is fully warmed within 4 blocks of "startup" driving. Can a 0w raise MPG in a way that the change can actually be measured? Or does it raise your MPG from 36 to 36.2, for example? Cheers!

 

[AEHaas]

Your water temperature is up in the initial few minutes of driving. Oil takes a minimum of 20 to 30 minutes to reach 180 - 200 F, operating temperature. Most people actually reach operating temperature infrequently and actually operate with "cold" oil as I see it. This may help you understand the situation: These may help you understand viscosity, the first one is more complete: http://ferrarichat.com/forum/faq.php?faq=new_faq_item#faq_haas_articles http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=259902#Post259902 aehaas

 

[JHZR2]

The selling point behind a 5w-30 vs 10w-30 was better startup fuel economy. Lots of folks take lots of short trips around when our oil isn't hot. Eeeking out a bit better economy there is good, and if the marvel of modern technology allows for a shear stable 5w-30, then all is well. Now, modern technology allows us to have stable 0w- oils. At operating temperatures, very little is gained. At startup, marginal protection is gained, but the lower vicosity can lead to better fuel economy again. If ten million cars in the fleet gain 0.1 MPG, you start to see reductions in fuel use, even if to the average user, it is not noticable from the noise. You have to think on a widespread basis. JMH

 

[xBa380]

That is the reason I am running 0W20, not for the MPG gain (if at all), but added protection when not at operating temp. I do make quite a few short trips that don't get to operating temp and just want as much protection as I can get.

 

[ToyotaNSaturn]

I would think that the most measurable differences would be in cold weather. I doubt hot summer weather would show much difference between a given 0w & 10w spec oil.

 

[pbm]

I am still using 10w30 in the warmer months in my Buick 3.1 (which specs 5w30 year round). Why? Because I have a ton of it in my stash. I doubt that there would be much difference in wear or mpg in the warmer weather.

 

[garyoNC]

AEHaas I do enjoy your articles as they are very well written. They have helped me a great deal in my understanding of oil and how it interacts with engines. I do have a question though, I have seen a few references where you talk about updating your articles. Would it be possible for you to include a date by your name at the beginning so we know when you have made changes? Especially now since some new technologies and grade changes are going to be released and I'm sure you will give us the skinny on it all. Again, good job and thanks for posting your info.

 

[oilyriser]

Perhaps the 0w has more shear related temporary viscosity loss.

 

[BuickGN]

 Originally Posted By: xBa380

That is the reason I am running 0W20, not for the MPG gain (if at all), but added protection when not at operating temp. I do make quite a few short trips that don't get to operating temp and just want as much protection as I can get.

I have my doubts that a thinner oil provides more protection when cold. The tests I've seen showed that more wear occurs before the oil warms up, regardless of viscosity.

 

[Solo2driver]

 Originally Posted By: AEHaas

Your water temperature is up in the initial few minutes of driving. Oil takes a minimum of 20 to 30 minutes to reach 180 - 200 F, operating temperature. Most people actually reach operating temperature infrequently and actually operate with "cold" oil as I see it. This may help you understand the situation: These may help you understand viscosity, the first one is more complete: http://ferrarichat.com/forum/faq.php?faq=new_faq_item#faq_haas_articles http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=259902#Post259902 aehaas

Interesting reads!

 

[demarpaint]

How cold does it have to be for a 0W-x oil to have an advantage over a 5W-x? Thanks, Frank D

 

[demarpaint]

Also, and what confuses me is if a new car calls for 5W-20 or 5W-30 why not spec 0W-20 or 0W-30 for the added cold start protection??????? I asked Chrysler in an email if I could use 0W-20 in my new Jeep which calls for 5W-20 and was told it would void the warranty. Frank D

 

[Bambam]

 Originally Posted By: demarpaint

Also, and what confuses me is if a new car calls for 5W-20 or 5W-30 why not spec 0W-20 or 0W-30 for the added cold start protection??????? I asked Chrysler in an email if I could use 0W-20 in my new Jeep which calls for 5W-20 and was told it would void the warranty. Frank D

I think they don't recommend them casue most consumers are oblivious to oil and fear that it's too thin! Using an 0w vs a 5w,the burden of proof is on them to prove that the sole reason you had a failure was cause 0w was used instead of 5w,highly unlikely there will ever be an oil related issue with an engine besides complete and utter neglect!

 

[heathenbrewing]

Thanks for the input all!

 

[heathenbrewing]

 Originally Posted By: AEHaas

Your water temperature is up in the initial few minutes of driving. Oil takes a minimum of 20 to 30 minutes to reach 180 - 200 F, operating temperature. Most people actually reach operating temperature infrequently and actually operate with "cold" oil as I see it. This may help you understand the situation: These may help you understand viscosity, the first one is more complete: http://ferrarichat.com/forum/faq.php?faq=new_faq_item#faq_haas_articles http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=259902#Post259902 aehaas

You have provided me your articles in the past....EXCELLENT reads! Thanks again. But I find it hard to believe (not saying its not true though) that such a blanket statement of "20-30 minutes" can be made. May be a fair "average", but things like quanity of oil in circulation, outside temps, speed, etc. seem to play a vital role. As for my vechicle, for sh!ts and giggles one day, I took a laser temperature gun from work (shoots a laser out and reads the temp of the object it hits) and took it home with me. After my 8 minute ride to the gym, I "shot" the oil filter and it was almost 200F.

 

[Gary Allan]

 Originally Posted By: ToyotaNSaturn

I would think that the most measurable differences would be in cold weather. I doubt hot summer weather would show much difference between a given 0w & 10w spec oil.

I didn't see a whole lot of difference in "time to temp" between subfreezing and 80-85F. The number may have been 10-15F different ..but the curve was basically the same. That is, the trip to matching (the higher) ambient isn't so far in time/miles. Barely enough to notice. The big stretch is from like 160-200F+ as you approach normalized temps.

 

[Steve S]

 Originally Posted By: BuickGN

 Originally Posted By: xBa380

That is the reason I am running 0W20, not for the MPG gain (if at all), but added protection when not at operating temp. I do make quite a few short trips that don't get to operating temp and just want as much protection as I can get.

I have my doubts that a thinner oil provides more protection when cold. The tests I've seen showed that more wear occurs before the oil warms up, regardless of viscosity.

Is is other things that cause warm up wear.

 

[mechtech2]

There is no lower limit for a '5' weight. So this leaves us to find out the individual characteristics of any particular oil.