salad

Hey, a jug of SA would be pretty neat to find.

sycoglitch

Ive used th Mobil super HM for the winter. Jeep likes it

PocketsEmpty

I ran Mobil 5000 for a few years before switching to Rotella T6. I never had a problem with it, but my vehicles are much happier with the T6!

Firestorm500

My 4.0s aren't very late. '87, '92, '97. As I said earlier, Mobil 1 10W-30 and Wix FTW.

Firestorm500

How do you know they are much happier?

PocketsEmpty

They run much smoother and quieter. The 4.0 quieted down a lot and runs smooth as silk. The 2.2 in my daily driver has a condition where the hydraulic lash adjusters will tick heavily if the car's been sitting for 2 days or so while the oil drains out of the head. That issue is totally gone with the T6, and starts up and runs smooth with zero ticks. T6 5w40, FTW!

djb383

.....might be worth something too since it is obsolete in engines built after 1930......but hey, a tractor motor is a tractor motor, right?.....so it should work fine.

I guess some folks just can't see the advantage of a 0W or a 5W oil flowing to the top of the motor (the valve train) quicker than 10W.

MUKAK

hey Salad which Rotella do you recommend for my 89 Renix 4.0 with 280k miles on it? Rotella 5 or 6? and what weight? i am in cali and its my daily driver

thanks

salad

lol

Well ancient junk is all the same, apparently, even if the design never changed...

That's a very vague question. To answer it properly requires knowledge of your cooling system health, ambient temperature, driving habits, and vehicle history.

So use whatever grade your engine likes the most. Some engines don't like 40 weights. Go buy whatever you feel comfortable with and give it a go. Lighter oil is better for fuel economy, every time.

Remember to get a quality filter.

Firestorm500

"Lighter oil is better for fuel economy, every time."

This stuff ends up being 30 or 40 weight by the time it approaches operating temperature. Oil spends very little time at the 5 or 10 weight. Any fuel economy savings would be unmeasurable in the average engine.

According to bobistheoilguy.com, even 0 weight oil is too heavy to immediately flow upon start-up.

Firestorm500

Mobil 5000 was a cheap, trashy oil. Hence my auction comment earlier. I'm glad you got away from it.

djb383

.....but both 0W and 5W will certainly start to flow quicker than 10W, no?

sycoglitch

According to that link earlier its true, although they have a lower starting viscosity its still too much for qn engine. But the 30 weights all become a viscosity of 10 at normal operating temperature. That link was the best thing ive read in a while

jopez_89

Update: so like you all know I switched to synthetic a few days ago, all was well until this morning......it was about 30° outside this morning when I went to start her up. Immediately I noticed piston slap, very lightly but it was there. Almost sounded like a really quiet diesel engine. After it warmed up it went away. I will probably be switching back to dyno oil here shortly. Anyone use castrol gtx? Im really hesitant to use an oil made for diesel engines (rotella).

884x4

I put rotella 15w-40 in my brand new 4.0..lol, stuff is cheap at Wal-Mart
Pair it with a Napa gold filter and it's awesome