Posts: 436. 15w40 "diesel" oils tend to have more additives (like zinc) as well as more detergents. That's what makes them better. The 15w40 oils seem to make all Mercedes -- gas or diesel -- a little happier. Down here, however, my 450SL prefers 20w50. It tends to find ways to leak 15w40 more readily in the heat!
Hi. I still can't choose between those two oil weights. To stay with 10w-30 Or to move to 10w-40 at 280k. I been using both and noticed slight difference Using 10w-40 in increase of gas mileage, but better protection than 10w-30. Any comments,advices?
This embraced a wide range of engine types, applications and a temperature range from around -15C to >40C. During the 1990s Castrol trialled a semi-synthetic 15W-40 which was in an evolving prototype form in my engines (much like Formula 10W-60 some decades earlier). I was able to compare mineral 15W-40, SS 15W-40 and finally a fully synthetic
Thin, low viscosity oils flow easier to protect engine parts at cold temperatures. The faster oil flows to critical parts of the engine, the more protected they are from wear. So a 5W-30 will flow easier than a 10W-30 at start-up temperatures. And a 10W-30 will flow easier than a 15W-40 at normal engine operating temperatures.
Xf3FQ.difference between 10w and 15w oil
