drhoward1988

I think it has been about 3 weeks. I've been using Mobil products for about 10 years now and they have always performed well(basic oil testing done from work). With your information though I may just have to switch to T6 for the jeep. Thanks again.

investinwaffles

What temperature range would be good for Rotella T (15w40)? I assume the southern climates, but at what temp would you switch from Rotella T to T6 (5w40)??

djb383

0W40 and 15W40 r the same viscosity at operating temp. The lower the 1st number, the easier/quicker the flow at below operating temp. I can't find 0W40 Rotella T6 on the shelf locally but as soon as I can, I'll switch from 5W to 0W.

salad

Well the original XJ manual cuts off the heavier startup weight at 30°F. Personally I think that's a little low and would aim for at least 50°F. My own driving habits have me at about three oil changes per year, one in the cold and two when it's warmer out. There's no reason technical reason against running 5w40 year-round but if you want to save money you could do your spring oil change with a 15w40. I'm going to be looking at Delo 400 LE this spring.

brian0128

Thanks for taking the time and putting this together.

ck1

Salad, Great write up....and it confirms what I have been using and telling people to use for years..Rotella...My Flathead runs so quiet on that stuff..This car has no oil filter and I used to go about 2k on changes. Had the oil tested a few years ago and was told no harm in extending change interval to 4k...and that is WITHOUT a oil filter (that was an option back then lol)...Zinc baby ZINC!..Rotella is the best IMHO
Cameron

pmondo

Thanks for the write up Salad! I just recently changed over to T6 last month. Im now thinking of running it in my turbo Jeep SRT instead of the Amsoil european blend.

PocketsEmpty

I was just telling the Blue Ribbon Fab guys about changing over to T6 when I had my rig at their shop, and they seemed interested in trying it. I don't think I'll run anything else now!

investinwaffles

Also, I just changed my T6 after an injector stuck open and fuel loaded my oil.

I mixed 3qt of Mobil 1 5w30, and 3qts of Penzoil 10w30 that I had lying around in my garage, with a Wix 1515 filter (only one I really feel comfortable running).

Hot idle pressure dropped from 25 to below 20, though it drives the same and feels the same at hot idle. Enough to warrant me swapping some T6 in as soon as I can afford it.

salad

If any of you gents get UOAs done while running T6 please post up, I'd love to add them here and get some more real-world data.

I just noticed that the two I posted are from the same guy

Demonoid369

So you share that T6 is best or at least the best but why do you still choose the delo? You mention you were goin g to use it when the weather gets better. I'm running the 10w t5 and I'm either going the t6 route or the delo you said. Figured if ask you why the delo lol

salad

Go back and re-read it then :P Monstrous load of boron, won't kill my cat so fast, and cheap (if I can find it). Mostly because I am really cheap.

highmileage

Right on Salad... good read.

Cherockee

How about throwing Brad Penn into your list?

http://www.penngrade1.com/Zinc.aspx

salad

Which grade? 10w30?