sirkfc

Has anybody done any measuring to see what kind of gas mileage improvement they get with 5w-20 vs. 5w-30? I know there are a lot of other factors such as engine break-in and weather that might skew the results, but maybe somebody has seen something really conclusive.

I just got my oil changed at a Toyota dealer, and they used 5w-30. I had asked for 5w-20, but they wanted to charge me $40 extra for it, because I think they only had synthetic blend. I didn't want to bother going to the store and getting my own 5w-20 and having to return, and I plan on changing every 5K anyway, so I said I don't care, just put in the 5w-30, since synthetic is a waste for 5000 miles usage.

Now I'm wondering if the MPG improvement over the 5000 miles would have been worth the cost and time.

Let's say I get 26 MPG with 5w-30. If I get 27 with 5w-20, then over 5100 miles, that's 7.25 gallons less gas used. At $3.55 per gallon, that's at least $25.80, making it compelling enough for me to remember to stock up on my own 5w-20 and taking it to the oil change place next time.

If there really is no difference, then I don't care. I live in CA and the car is garaged. Cold starts are probably not that cold in the scheme of things.

kickin8

iTrader: (1)

I dont think it has any difference at all........

weesped

iTrader: (8)

ya i run royal purp. 5w-20. i dont get any increase mpg vs. the stock 5w-30

GSteg

iTrader: (15)

You may get an increase, but the difference is pretty small. Probably less than 1mpg if that.

I myself run 5w20 on my GS400 even though it's spec'd for 5w-30, I did it more for protection than fuel economy. When your daily commute is 2 miles one way, your oil isn't heated enough lubricate the engine.

PhilipMSPT

iTrader: (5)

Insignificantly minimal.