[Bubba3200]

Any thoughts on using it in a 05 4.0. What about Deleo 15W40 I think it is?

[never monday]

no problem

[Bubba3200]

Benefits???

[never monday]

suposedly it's better for flat tappet engines because it had ZDDP in it. The new "low emissions" formulas of Delo, Rotella and Delvac don't have ZDDP, IIRC. I use it by the galon, so it's handy.

[Jerry Bransford]

Does it come in a little lower W rating as in 10W-40? If it has a higher zinc content, I'd be interested in running it in my 4.0L.

[robncar]

Here's some info on Shell Rotella T Triple:

http://www.shell.com/home/Framework?siteId=rotella-en&FC2=/rotella-en/html/iwgen/leftnavs/zzz_lhn2_0_0.html&FC3=/rotella-en/html/iwgen/products/products_home.html

[never monday]

30 w or 15w40 are the only ones i know of

[Unlimited04]

Even the diesel oils are cutting down on ZDDP, its all due to emissions regulations.

good readings:

The SAE publication from 1977 that started everyone thinking about ZDDP:
Cam and Lifter Wear as Affected By Engine Oil Zdp Concentration and Type

More:
Oils: What motor oil should I use? Which oil is best for my Porsche or aircooled engine?
http://www.andersonautomotiveenterprises.com/PDFs/techtips/new_oils_and_old_cars.pdf

GM also makes EOS (Engine Oil Supplement) to supplement ZDDP in all oils, which seems to be the recommended thing to achieve 1200-1400ppm. Look for 0.12% Zn on the oil bottle itself if possible tho.

[Bubba3200]

Valvoline high mileage oil good for the 4.0? I see in the high mileage oils there is some additive's that swell the seals etc. Any good amounts of zddp in these oils. There is so much read for the oils after a while it gets a little confusing. I know that most any oil will prevent engine failure but what is truely the best oil for the 4.0. I have tried a few different brands of oil and rotella 15W40.....the jeep just seems to like it the best so far. Had the dealership fix the rear main seal before it went out of warranty and I took a look at the oil pan and bottom of the engine and no signs of sludge or anything. Mechanic said it looked like it had 500 miles on it. 70,000 miles and running like a top and I would like to keep it that way for 200,000-300,000 miles. Thanks!

[Jerry Bransford]

Originally Posted by Bubba3200

Valvoline high mileage oil good for the 4.0?

Absolutely. Valvoline is a top-top tier motor oil manufacturer, it's tough to beat. I run Valvoline myself, it's a highly recommended brand.

[CTTJ]

I was informed by a NAPA rep. that I've done buisiness with for the last 25 years that NAPA motor oils were in fact Valvoline Oil bottled in a different package.
This way Valvoline creates thier own compatition thus generating more revenue

[jondotcom]

I ran delo in mine first oil change which coincided with lower mpg due to bigger tires and a lift.. so I've switched back to 10-30 for now but notice no mpg improvement. I will likely go back to delo or whatever 15w-40 heavy duty oil once I clear out my stock in 10w-30 I bought from wally world. As a side note, wally world sells the 5-qt packs of delo and others for ~9-10 bucks!

[TJW909]

I have been thinking about switching to 15W-40 I always have it around for the Ford 7.3. This summer after interstate driving in 95 degree heat with Valvoline 10W-30 in my oil psi was lower than I had ever seen before and really low at idle.

[wushaw]

Rotella 15-40 has worked fine for me for over 100k in my 4.0.

[aaonms]

Rotella T 15W40 – that’s the non-synthetic one, correct?
There is a 5W-40 in synthetic.

Also, can’t comment on the conventional NAPA oil, but their synthetic is Valvoline-made.