: anyone evr use 5w-40 oil?



CAD-E!
05-02-08, 02:37 AM
someone was telling me using this will get you better gas mileage.

hcvone
05-02-08, 08:05 AM
I have used 0-30 for year, Amsoil, of course it protects better than 20-50 standard oil and offers the best fuel mileage.

Daryl in KY
05-02-08, 09:47 AM
5W-40 is what Volkswagon and other European cars require. Usually lower weight oils provide less resistance to a shaft turning in a bearing. But the resistance depends on many factors: clearance, temperature, viscosity, etc. There may be certain conditions that 5W-40 might give better gas mileage, but for most conditions it will probably have better high temperature performance than 5W-30 and slightly poorer mileage.

A bigger factor on mileage will probably be the friction reducers that are added to many oil formulations and the ability of the oil to maintain its viscosity. The viscosity of many muti-weight oils change under use and the mileage can begin to suffer. An oil that starts out as 5W-30 can end up similar to a 15W-40 over time. The quality of the oil you use and the change interval can have a larger affect on mileage than using 5W-40 versus 5W-30.

CAD-E!
05-04-08, 03:50 PM
I have used 0-30 for year, Amsoil, of course it protects better than 20-50 standard oil and offers the best fuel mileage.

im driving down to LA this weekend and im gonna change my oil and try amsoil 0-30.


5W-40 is what Volkswagon and other European cars require. Usually lower weight oils provide less resistance to a shaft turning in a bearing. But the resistance depends on many factors: clearance, temperature, viscosity, etc. There may be certain conditions that 5W-40 might give better gas mileage, but for most conditions it will probably have better high temperature performance than 5W-30 and slightly poorer mileage.

A bigger factor on mileage will probably be the friction reducers that are added to many oil formulations and the ability of the oil to maintain its viscosity. The viscosity of many muti-weight oils change under use and the mileage can begin to suffer. An oil that starts out as 5W-30 can end up similar to a 15W-40 over time. The quality of the oil you use and the change interval can have a larger affect on mileage than using 5W-40 versus 5W-30.

yeah i remember seeing that 5w 40 was european specific.