Originally Posted By: Kenwood
I have a 2000 Toyota Avalon with 140k miles that calls for 5w-30 oil and am considering running ow-30 at the next oil change in hopes of a slight mpg increase. Is there any advantages or disadvantages to switching? I have been reading a few of these oil threads and the knowledge you guys have of oil is impressive.
Hi Kenwood, unless you're doing a lot of really short tripping with long cooldowns between trips you might see a little gas mileage benefit from using an XW30 that has a low viscosity for its grade at operating temperature (~100C for many gas vehicles).
There has been a lot of discussion here about recent changes in many oil formulations to meet dexos1 Gen 2 specs (GM standard for which most mass market oils are going to want to have a license) and we noticed that the last Pennzoil Platinum 5W30 has a lower viscosity at 100C (9.8 cSt) than, say, Mobil 1 5W30 (11 cSt). I would think that PP is still going to do a good job of protecting your engine and the 5W30 might result in better fuel economy than many of its competitors if you are making reasonably long trips where the engine is mostly warmed up.
Not a Pennzoil fanboy here, I have never used it in my vehicle but did just put some PP 0W20 in my daughter's Impreza.
If you end up doing a lot of really cold starts (like way below zero) where the engine has truly gotten down to the ambient temperature, I could see the 0W30 having some effect upon mileage compared to a 5W30 with a similar operating temp viscosity. But, I honestly doubt many people would see a gas mileage benefit from using a typical 0W30 vs. a 5W30 even in winter.
Just my two cents worth and welcome to BITOG!