Car uses about a quart every 6k miles with 5w30, which isn't much but I'd like to see if a summer run with 10w40 helps.

10w40 users, please feel free to share your experiences.

 

0w40 mobil or castrol

 

I use 10W40 year around. Have done this for years and years.

 

i only use 10-40 between oil changes or only when i have to add some. Lately 5w30 has been lasting me alot longer between oil changes after replacing the leaking oil pressure swich.

 

I use the high mileage 10-40 year round, but it still burns off a quart between oil changes

 

I used to use 10w30 for years til now I have been using 5w20 synthetic to get better fuel economy.

 

can u tell /feel the difference from the recommended 10w30 vs the 10w40 ?


i was doing 5w30 for a while, and then the same damn oil change shop changed me to 10w30 currently...

i thought 5w30 was a lil nicer for oil consumption

 

I can't tell any difference. I'm not a performance person, all I want is a reliable car that is to drive. My original reason for going to 10w40 was because I was doing a lot of highway driving and wanted the better protection for the sustained higher rpm on a hot engine.

 

5w30 is the recommended weight, but the manual says 10w30 & -40 can be used above 0F.

 

ok kool ! i just wanted to know the reasons for weights... i need to study oil mroe i guess. im not much a performance person either, just wondering if u felt it in the pedal or anything. thanks for input !

what do you like to use? is 10w preferred by you?

 

Consider using high-mileage oil, if you are losing it through the valve guide seals, it may help.

 

Why not 0w40?
It lubricates better at start-up (low temperatures, and I mean like 72'F), and is the same as 10w40 at high temperatures .....
Wallmart sells it for ~$25 for 5L jug.

 

I've mainly been using 5w30. I looked at UOAs and these VQ35s tear up oil for some reason. A 40 wt should protect against shearing.

I used M1 0w40 once and was impressed by how smooth it made the engine run. The peeps over on BITOG say on cold starts, an oil burner will burn a 0w more easily than a 10w. This is why I want to try out 10w40.

 

It doesn't make much difference in my experience. If the oil is a similar viscosity at temp and similar base stock (it's not b/c 0W has superior stock), then it would burn about the same.

If there's not precat damage, then the burning is from valve stem seals. I just swapped another motor and guess what? The exhaust valves were wet and had tons of carbon from the oil leaking down (engine had sat a long time, too, that's how much oil was still on them).

 

so my burning is from teh valve stems seals.... what else should I know? oil catch can worth anything in that specific case?

am I good at staying at 5w30 vs 10w30 ??

 

thanks for your input ! 5w30 has been feeling nice too along with TCW3

 

Delete PCV and that solves oil in the intake. You will burn some from blowby, but those stem seals are so ****ty. I could engine brake for a few seconds (pull some sweet vac), then upon acceleration, it'd blow a thick blue cloud. Rings aren't gonna do that.

 

broken pistons/rings smoke is going to pour out the valve cover

 

For anybody that cares, I decided to try MaxLife 10w40 for the summer. 2k miles of mixed driving and dipstick is still full. Engine purrs like a kitten. MPG is still the same as before.

 

I run Shell Rotella 5w-40 in everything, even my motorcycle... it's good stuff

 

0w-30 in winter, 5w-50 in summer.