Good morning everyone -

So, I have been reading a bunch on the 5w-40 Synthetic Oils and think this is the way I want to go in the future. I currently have a 89 F350 with a 7.3 and plan to allocate a 97'ish Powerstroke in the not too distant future.
here is a lot of good information floating around, but with all the CK-4 and CJ-4 stuff floating around, I'm cornfuzed .

I am trying to find a good oil that will help either of these trucks with cold start ups, but also perform well in all other aspects. I am not looking to run any crazy long oil change intervals, probably the 3-5k mark.

Let me know what you guys think regarding the new oils in the older technology engines, any issues?

There is not too many recent threads regarding the early 73.L IDI's or the 94.5-97 Powerstrokes. Maybe..... That's because it doesn't matter

Thanks in advance

 

In your temp's I would defiantly run synthetic.

 

Thanks oldbird, I definitely plan to run synthetic, I just wanted to make sure and not inadvertently choose a 5w-40 that was not a good match for the old 7.3's.

I guess when I get home around the end of the month, I will have to look around locally to see what is available, the pricing and go from there.

 

I have only owned 2 diesels, an 01 dodge with a 24 valve Cummins and the 97 f250 I have now with the 7.3 powerstroke and I run rotella 15W-40 in both and have never had an issue with either. I had 330k on the dodge when I sold it with the original motor and stock internals, and my f250 has almost 330k on it. I personally don't think you need to run synthetic, but I won't argue science or research behind synthetic. I've just never heard of somebody having an issue using either or either helping improve an issue.

 

My main situation I want to possibly help out is cold weather starting.

From experience on my previous Powerstroke, during cold weather starts, it would crank much slower, take longer to light off, as well as it had a pretty good romp/romp to it when it finally started. Now, keeping in mind, a lot of those issues could have been partially caused by many, many things. In that truck, I ran the Motorcraft 10w-40 Diesel Oil.

I definitely do not think it is a "need", just more of a helping hand when our weather dips below 20°F for a couple months. Where I live, we do see some sub -10°F days, but they are not as often as the guys that live in the upper 2/3rds of the state.

 

AK ~= AZ... Yes, the truck would probably start on 15W40 up there. But cold starts are when the bulk of the friction wear occurs, and anything that alleviates that (such as a synthetic 5W40) will help the engine last longer.

 

Hi Guys My question is Will the syn oil make the engine a oil leaker? I ordered my truck way back in 1994 Nov.& received it In March 1995. It,s a F350 srw 4x4 Auto. I have always run Rottella 15-40 & changed it between 3 & 4 thousand miles. Usually @ 3 thousand. I do it myself. I,m a retired heavy duty mechanic.The truck now has256.000 miles & with the new oil spec,s I,m wondering about going to sny, oil in place of the C4 rottella? I do have a whole bunch of things that I have done to the truck engine & the auto. Thank you for any advice. We are hear to learn. Friskyjake

 

From what I have learned and done myself the answer is NO.

 

There is a very long thread over in the 6.7 thread regarding CJ4 and CK4 spec oil. It gets a bit muddy with all the arguing.The short story is CK4 spec oil is based to be EPA compliant with the new DPF and catalytic systems of the new diesels. We do not care about this with out trucks however they lowered the count on Zinc, moly, and phosphorus in the oil, which our motors were initially designed to have, as diesel was not initially ultra low sulfur and was only low sulphur during the day of the 7.3. when our trucks were designed. In essence it the lubricating factor for our motors. Run ANY CJ4 spec 5/40 oil and you will be leaps above a dyno oil. Delo, Valvoline, the NEW X3 T6, and so on are all good oils, Rotella just got in a bit of chit as they were labeling CK4 spec oil as CJ4 for a couple months when it was not...This is my opinion but has been backed by multiple blackstone results by forum members here and many other web sites.

There are a ton of threads out there backed with Blackstone results on "BOB IS THE OIL GUY" website that you can over analyze to no end. Plain and simple a 5/40 CJ4 synthtic will be a much better oil in AK or even TX for that matter. The HEUI system and HPOP of a 7.3 shear standard non synthetics quicker than say a cummins or non HEUI motor. You will not do any harm running a good synthetic vs a non. It will help with cold starts as well. Go read up if you are truly curious.

 

Agreed on bobiatheoilguy.com

I would 100% run a true syn 5/40 in an extreme climate for cold flow properties alone, maybe a lighter Diesel rated oil if could be found. Most true syns flow better at same weight of dino anyway.

Hell, it only drops into mid teens here at lowest/low 100s highest and I would run it if I was not consuming it. Ran Redline in the 6.4 for years.

Zero harm is done switching from a dino to syn, regardless of mileage. Did a car I had around 150k and it to 270k before trading it off. No more problems than another.

 

wilsson - Thank you, for some reason, I completely forgot about BOB THE OIL GUY.

 

There have been some reports on higher mileage engines that used Dino oil throughout its service. When switching to synthetic oil leaks appeared. Don't know the science behind the issue but it could occur, probably a leak just waiting to happen. Think that was one of your questions.

 

Leaks were waiting to occur. Syn creating leaks is an old wives tale, like current yellow bottle Pennzoil is on par with pouring candle wax into your engine.

I swapped another of my cars over from dino to syn. No more leaks than one would expect at that mileage! Did the change over at 230k, car now has 320k. That is a gasser. Two other Diesel cars I own have done the same for easier cold starts and better OCI. No issues.

 

Guess then I stand corrected sir ...

 

Are the folks running T6 stretching chance intervals out any or still changing every 3k?