holy_crap

Has anyone tried 0W-20 motor oil on their Jeep? I have always used the recommended 5W-20 and it has always been a full synthetic on all my vehicles. I have heard on here of some people using 10W-30 on their Jeeps as well. I wonder if going with a lower viscosity oil, especially on a brand new engine will improve gas mileage a bit.

I got this from the Mobil 1 site on their explanation of engine weights. "The lower the number (0W is the lowest), the lower the temperature the product can be used. So the W grade is related to the lowest temperature your engine sees when you start the engine on the coldest morning of the year. But also keep in mind that a lower W grade pumps and helps an engine to start better than a higher W grade".

Explaining Motor Oil Viscosity Designations

Any thoughts?

familytime

It would be like running straight 20w.

Incawrangler

I've personally never ran it, but I hear that 5w30 is probably the all around best for summer months because it's not like putting water in your jeeps engine, it's a little thicker and cuts down on all the crazy noises a jeep my make when it is in idle.

Jeepstin12

The first number is the cold flow and the second is the hot flow grade. The lower the forts, as you stated, allows the oil to flow and protect until the engine warms up. It really all depends on where you live, what your weather is like, etc. I run 5-30 pretty much all year. In my Volvo, 0-40. I ran 0-50 Amsoil on my dodge a Ram and 0-40 in my land rover.

ZMagic97

Being in Florida, I'd run 10W-30.

Jiblet

You'd never see a difference with 0w-xx vs 5w-xx until you got subzero weather (even then...) And the difference in mpg is negligible for an individual. Either would be fine for the jk. But so would 5w-30. Realistically, the brand oil is probably more important than any of those three grades. Any of the top name brands won't let you down.

SN/GF5 oils are spectacular, conventional or synthetic. These engines don't need anything fancy. At $25 a 5qt jug at Walmart you can't really beat M1 or the new pennzoil GTL formulations. Follow the manual and OCI. And check the dipstick. Often.

Chefbrujo

I saw some research from petroleum scientists in the oil biz say that 0w and 5w provide better long term protection against engine start-up wear. And that seems to be the only benefit outside of living in freezing conditions.

Biggy

I've run 0-20 amsoil from the time the Jeep was new. It doesn't burn a drop with 80000 km. I'm up in frigid Canada.

JKZinger

0w will cause less wear at startup than 5W no matter where you live. It is the cold oil number and has no bearing on the ambient temperature once the engine is warm.

sillybubba

I used to run 0W 30 oil in my vehicles during the winter here in canada. Would never use it in the summer. In my thinking the 0 weight oil would drain almost 100% in to the pan if the vehicle sat for a while so every start up would be dry. I really dont even like using a 5 weight in the summer