Oil Recommendations

I average 21-22 mpg regardless of oil weight. I normally did 5W-20 Mobil1 but this time around am on Royal Purple HPS 5W-30.

I do notice my motor is quieter on the 30 weight (anecdotal ear dyno)

I heard somewhere (also anecdotal!) the 20 weight was strictly being used for fuel economy purposes and 30 weight was more appropriate for the Coyote.

I Dunno, I like olive oil the best....yum!

RedRyan98 said:

It should be the opposite, no? Colder air is denser which requires more fuel to burn. I was under the impression that, all else being equal, fuel economy should increase when its warmer out.

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A combustion engine is an air pump. The more air, the more power.

Denser air, means better efficiency for the engine, thus better gas mileage.

whalesalad said:

...the 20 weight was strictly being used for fuel economy purposes and 30 weight was more appropriate for the Coyote.

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This is correct. 5w-20 exists ONLY to improve FORD's overall fuel economy standards. It has nothing to do with engine protection.

Some of the misinformation already on this thread is one of the reasons I really do not like buying used cars.

In response to my comment above, I only run 5w-20 (Mobil 1) in the winter, and 5w-30 (NAPA synthetic) in the other 7 months of the year.

Yes, Iowa has 5 phucking months of winter!!

Im running 5w30 mobil ext perf. Last trip to ocean city got me 24.5 mpg. Cant beat over 700hp and 24mpg

VooDooDaddy said:

In response to my comment above, I only run 5w-20 (Mobil 1) in the winter, and 5w-30 (NAPA synthetic) in the other 7 months of the year.

Yes, Iowa has 5 phucking months of winter!!

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I would die in 5 months of winter.it’s bad enough here in winter when it gets down to 6/7c …strongs to I guys I won’t moan again about our cold winters in Cape Town

Whatever synthetic is on sale. I do like going up a grade though...seems to keep this clattery pos quieted down...

You guys bringing up a 5.5 year old thread. A topic that has more opinions and disinformation on the internet than maybe any other automotive related topic.