viscosity and weight to use

[wjs81866]

I have a 98 Grand Cherokee 5.9L V8. it has 70,000 miles on it and I'm currently in the cleaning phase of Auto Rx. After that is completed I wanted to switch to synthetic (Probably Mobil 1 or Royal Purple?)

I generally drive it to/from work mostly highway about 20 miles each way. Sometimes I use it offroad (Not serious) I don't have a garage but do have a block heater. I bought the truck used at 66,500 miles; it seems to have been well maintained.

I have been using Havoline Dino (10W30) with a Napa gold filter to change the oil to this point.

My question is once I go to a synthetic; should I stick with the 10W30 or would it be better to go to something else? The spec calls for 10W30 in any temp range.

The reason I want to switch to synthetic is that I feel it would be better for the engine overall for cold starts in the winter. Northern Illinois can get pretty nasty for a few weeks usually with temps sometimes falling to close or below zero especially at night. Plus I plan on driving this well past 100K miles and feel this would help make this possible by reducing engine wear compared to regular dino oil.

 

[unDummy]

Any 10w30 synthetic will work well year round.
But, I'd recommend 5w30 or 0w30 during the winter months.

 

[wjs81866]

Quote:

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Any 10w30 synthetic will work well year round.
But, I'd recommend 5w30 or 0w30 during the winter months.

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ok, thanks for the reply. That being said; at what approx temp do I go back to the 10W30?

So at (I don't know around 30 deg F. I could run 5W30 or 0W30 but then when it starts getting up to?? deg F I should switch back to 10W30?

 

[Maximumcanon]

isnt 0w30 and 10w30 pretty much the same thing during the summer? (excluding differences between oil companies). so souldn't it be better to use 0w39 year round?

 

[unDummy]

Some will argue that the 0w and 5w oils have excessive VII/PPD's in the oil. The synthetic 10w30's supposedly can be blended without excessive additives needed to meet required CCV/MRV specs.

If you change the oil 3-4 times a year, just anticipate the weather. Because winter is coming, my cars are all getting 0w or 5w oils at the current/next OCI. In the spring/summer, I'll move up.

Yep, you can use a 0w30 or 0w40 oil year round. Some are rumored to shear a little because of the previously mentioned additive dosing. Not an issue if you change your oil a couple of times a year. It is an issue if you try to use the oil forever. I usually use 5w40 year round. But, I've had a couple engines that prefer the M1 5w30 during the cold winter freeze. I don't garage my vehicles and none have block/oil heaters.

I also find that synthetics work so much better then mineral oils in the winter, even with the same bottle specs. I ran M1 15w50 in a PRV 3.0 v6 year round. It actually hated(much noise/clatter) 10w30 and 5w30 mineral oils in the winter. Unless you're SantaClaus, the difference with the full synthetics in the 0w, 5w, or 10w isn't much of an issue. But, I find it noticeable with the mineral oils.

...........early--late
summer 15w or 10w
fall...... 10w or 5w
winter.... 0w
spring ....5w or 10w

visit weather.com

 

[wjs81866]

Thanks

I'll keep that in mind