what do you think about using rotella t synthetic 5w40 in a 1997 jeep 4.0 grand cherokee with 95k on it and a 1998 ford f150 4.6 with 82k on it.im currently using 10w30 in both cars right know.will the 5w40 be good for winter?to my understanding is that it will couse its 5w? or stay with 5w30 for the 4.6 f150 and 10w30 in the 4.0 grand cherokee year round.i would really like to find an oil that i can buy by the case and do both oil changes to both cars with the same oil grade. any comments please ....tks
rotella t synthetic5w40 question?
- Thread starter aztec12
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Standardizing would be nice, but alas..., if you don't absolutely have too, I wouldn't. The Jeep seems to like thicker and the Ford requires thinner.
I think the Rotella would be ok for the Jeep, but a bit too thick for the Ford in N.C., especially in cooler temps coming up.
I think the Rotella would be ok for the Jeep, but a bit too thick for the Ford in N.C., especially in cooler temps coming up.
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I wouldn't sweat it in your climate ..or in just about any that I can think of. The jeep could care less ...and what's the worst thing that anyone can reasonably expect out of using it in a 4.6 Ford???
Try it and if you don't like it (based on REAL results..not anything nebulous) ...don't use it in the 4.6. It's not like getting married.
Try it and if you don't like it (based on REAL results..not anything nebulous) ...don't use it in the 4.6. It's not like getting married.
Well, you've found a perfect guinea pig in me, as my current fleet at home is an '88 Jeep Cherokee with the 4.0l and 65,000 miles (no, not a typo!), and a '99 F150 with the 4.6 and 108,500 miles.
Right now, I run both on Rotella T Syn 5w40.
On the Jeep, run the Rotella T 5w40 without any worries. I've been running it close to a year now, and so long as my last UOA I just sent in shows some improvement from the the previous one, I think I will stick with the 5w40. No dropoff in fuel mileage from the previous 5w30/10w30 regimen. Runs nice, no leaks, and no fade in oil pressure when running hard, which I had observed using 5 and 10w30 oils. Starts fine in Minnesota winters.
As far as the F150 with the 4.6 goes, the jury is still wayyyy out - this is my first interval using it, and I just took a sample a few nights ago. My observations to date are: Clatters more on cold startup than with 5w20 or 5w30. (Same oil filter). Noted decrease in fuel mileage versus 5w20 or 5w30 (currently about 4% lower - and I have meticulous fuel records to back that up!). My Butt dyno says the engine feels more sluggish and the engine is less willing to rev, but we all know how accurate those measurements are.
In other words, unless my used oil analysis start coming in suggesting lower wear than I acheived over running 5w20 or 5w30, I don't think 5w40 will have a permanent home in the 4.6. Like I've said though, I'm keeping an open mind about it, and we'll see what a years worth of used oil analysis look like.
I'd like to only keep one oil around too, but my guess is that in a year, I'll have gone back to 5w20 or 5w30 for the F150, and stuck with the Rotella 5w40 in the Jeep...
Good luck!
Right now, I run both on Rotella T Syn 5w40.
On the Jeep, run the Rotella T 5w40 without any worries. I've been running it close to a year now, and so long as my last UOA I just sent in shows some improvement from the the previous one, I think I will stick with the 5w40. No dropoff in fuel mileage from the previous 5w30/10w30 regimen. Runs nice, no leaks, and no fade in oil pressure when running hard, which I had observed using 5 and 10w30 oils. Starts fine in Minnesota winters.
As far as the F150 with the 4.6 goes, the jury is still wayyyy out - this is my first interval using it, and I just took a sample a few nights ago. My observations to date are: Clatters more on cold startup than with 5w20 or 5w30. (Same oil filter). Noted decrease in fuel mileage versus 5w20 or 5w30 (currently about 4% lower - and I have meticulous fuel records to back that up!). My Butt dyno says the engine feels more sluggish and the engine is less willing to rev, but we all know how accurate those measurements are.
In other words, unless my used oil analysis start coming in suggesting lower wear than I acheived over running 5w20 or 5w30, I don't think 5w40 will have a permanent home in the 4.6. Like I've said though, I'm keeping an open mind about it, and we'll see what a years worth of used oil analysis look like.
I'd like to only keep one oil around too, but my guess is that in a year, I'll have gone back to 5w20 or 5w30 for the F150, and stuck with the Rotella 5w40 in the Jeep...
Good luck!
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