06-15-2007, 09:52 AM
HAULN-SS Wrote:So, just to jump in on this discussion to clear things up - why does it seem like bigger engines call for stuff liek 10W-40 (read it on the internet) and smaller engines for 5W-30? Is that just something to do with power conversation? I'm assuming thinner oils dont rob as much power, and that counts for more on smaller engines?
Engine tolerances as well. Bigger engines usually have larger ones so they like a heavy weight oil. Sometimes if you get a high mileage engine where the gaps have opened up a bit and it's burning oil you can run a straight heavy weight oil like 40 weight and it will stop burning oil since it's so thick. I've never owned an engine as loose as a DC hooker so I've never ran straight weight heavy oil. Also newer cars are calling for light weight oils for emissions reason. I refuse to run like a 5w in anything I own, so it's usually a 10-30w.