2500

valvoline full syn $2.75 qt at advance auto parts until March 1, 08

only three choice of weights:

5W-30
10W-30
20W-50

lots of negative feedback on running 5W-30, so that's out unless I'm in extreme cold.

in Tulsa, OK. it can get HOT in summer and down to zero in winter, but not for long.

spoke with valvoline tech, stated 10w-30 will meet cummins spec's.

of these three choice... which is best for my 97 CTD?

Hillcountry

You need to run C rated oil for compression type engines. As long as it is an oil rated to use in diesel engines. Oil for gasoline engines does not have the ability to suspend and hold the soot and it will leave bad deposits on your engine. This can clog the cooling jets on the pistons and destroy your engine.
It is also not designed to coat the parts the same way. So don't use it.

If it is c-rated it will be fine. If not don't use it.

2500

5w-30 and 10w-30 Rated CF and GF-4

valvoline tech stated 10w-30 is rated for cummins spec's and new power stroke diesels recommends 10w-30 syn power

leaning going with 10w-30 syn power unless I hear other wise...
hard to pass up a $2.75 pt deal or 1/2 price. been resisting going to full syn due to cost trade off.

2500

any other opinions...

Hillcountry

Cool...it will also usually state on the label somewhere "meets specifications for ....(cummins will be in there)"

I agree the price is hard to beat.

GAmes

The thing is, with our old 12 valves, the oil needs to be changed just as often with either dino or syn because of the soot. Extended changes are great on the newer, cleaner engines, but I have read multiple articles stating that the older Cummins require clean oil more often. I never go more than 5000 miles and usually change at around 4000.

supr

I think you can get the CI+4 from Cummins, the old #1 rated Valvoline blend with the best TBN numbers. If it is not CI or CJ rated, I would not run it.

wcbcruzer

I dont' know. I wouldn't use either. How about Rotella Synthetic. $17/gallon at Wally world.

HOHN

These oils do not meet specs for your truck. Your truck requires a CG or later rated oil. CH would be better, with CI-4+ being best.

These aren't diesel oils, they are gasoline oils and you'd be well-advised to pass on this tempting offer.

What it's worth saving a few bucks when you have premature cam and lifter wear?

JMO

Blast Chamber

I'd have to disagree with this. According to my recent UOA from Blackstone while using Shell Rotella Synthetic 5w-40 for 10k miles there was no problems noted. Your results may vary, I guess.

wcbcruzer

Yeah, today's oils can be run much longer. The traditional saying: "Change your oil every 3,000 miles" is old skool.

BigErksG2

Great post Blast Chamber... nothing beast an opinion with good reasoning behind it! im planning on a 10k mile interval on my synthetic rotella oil this winter and 5k miles on my dino 15w40 over the summer.

GAmes

You should read this article. Of course, it is your engine, your money, but I am nearly at 600k on the odometer and over 600k due to odometer error. I think $40 every 4000 miles works out to be less expensive than an engine change, even if you do your own R & R.

Here's an excerpt;
Finally, don’t fall for the statement that synthetics can be costjustified
because they can be used for twice the normal oil change
interval. This is simply no longer true. The additive package,
particularly detergent, dispersant, and antioxidant levels, is the
primary determinant of oil change interval. Also consider that
extending oil change intervals is a gamble. You can monitor used
oil data to determine if sufficient additive is present to continue,
but one of the main reasons to change oil is to get contaminants
(soot, sludge, etc.) out of your engine. Some contaminants, such
as glycol, can cause a lot of damage in a short time.

Here is the article, don't know if non-members can get to it.
http://www.turbodieselregister.com/I...AnalysisII.pdf

So, BigErks, are you saying my opinion has bad reasoning behind it?

HOHN

The owner's manual recommended OCI for my truck is 7500 miles, or half that for "severe" use-- using petroleum oil.

I'm using better oil and better filters than the factory spec was formulated for, and I change at 7500.

I personally do NOT believe in extended drain of the kind some oil makers recommend (25K? C'MON!). But I see no problems at all running an oil like Redline to 7500 miles (Redline has the most robust additive package in the entire TDR oil survey).

JMO

GAmes

I concur, but you have a 24 valve, which is a cleaner engine. The 12 valve is 6000 mile interval for light duty use. What is the point of having a CTD and not using it HEAVY!!!???