What are the consequences of putting in 3 quarts of 10w-30 and 1 quart of 10W-40 at oil change ?

Thanks

 

Mixing viscosities is all right. However, Nissan prefers 5W-30. Cold-start engine noise has been attributed to thick oil.

 

100% corect, basically you would end up with a a viscocity of 10W-32.5, which is OK as long as your car can run in those parameters. But if a Maxima is supposed to run 5W-30, then do it or next time you take a corner at high revs you might drop oil pressure low enough to spin a bearing and f*** your engine. Don't screw around by putting in the wrong oil in order to save yourself $15. The consequences could be DISASTEROUS!

 

Service manual lists 10w-30 and 10w-40 for temperature higher then 0 F and 20w-50 for over 50 F. So if you don't drive around the north pole - that's ok. And pressure with the thicker oil is always higher than with 5w-30, no matter what revs are. That's why 5w-50 and 15w-50 recomended for heavy duty driving.
Alex.

 

Which service manual? Not mine.

 

i just bought a whole box of mobil 1 synthetic 10W-30 motoroil..is 10W thicker than 5W? also, does this mean my gas mileage will suffer if i use this stuff for summer driving?

 

Sorry, it was user's manual for 95 maxima.

 

It should be okay. But in the future, try to avoid 10w40 oils if they are dino type. It's a really big viscosity gap for the dino oil to maintain.

 

Yes.

Yes, but by only a small amount. Go ahead and use the oil you bought.

 

10w30 and 10w40? I have always used 5w30 in my 92 and 99 maxima. When i used 10w30 in my 99, i lost about 20-30 miles per tank. My manual says to use 5w30 and when i worked at Jiffy Lube, all that was used was 5w30 as well. Just my 2 cents though.

 

I live in FLA and when I use to use 10W30 or 10W40 would experience a little engine noise on cold starts. I now use 5W50 Castrol Syntech and no longer get that noise. Also make sure the filter you use has the valve in it to keep the oil from draining down into the pan. It looks like a spring inside the filter, and it's not on all oil filters which are sold for our cars.

 

I am using 10w-50 fully synthetic.