:stirthepo Ok I've just done another change at 43,700 on my 03. Between a trip to FL in late Feb, and TN over Easter weekend I cranked up a few miles in that month.

I just bought two 5qt jugs of the Mobil Truck and SUV and a Mobil 303 Filter(since I just depleted my Baldwins). From VOA's that i've seen on this oil it is essentially Delvac which is arguably one of the best oils out there for our trucks, and the syn filter is also arguably the best spin on full flow.

I've been changing every 5000 +/- miles(5600 on last with Rotella Syn). Since I'm supposedly running the "best" I'm going to extend out my oil change this time and do a UOA at 5k to see where it sits, then probably a followup at 7500k etc, to see how far this oil in a non dual setup will run.

SO my question to some of the more knowing people out there, is if I change the spin on at say 5k, run the analysis shortly afterwards would that help the oil life? My thinking is that since this filter is super efficient whatever makes it's way into the oil is going to stay there since it's too small to be caught by conventional means, or am I off target there? Or does this apply like most filters that they become more efficient as they get dirty until they
'round the bend' and start to lose filtering capacity?

Just wanting some feeback, since I may go the Mobil extended drain on the wifes T-blazer as well. Yes I know, oil is cheap but there's more fun things to do than oil changes. ):h

Yes, it will help your oil life. Why? Because you are taking out 1 quart of dirty oil, and replacing it with clean oil. The 1 quart of new oil will contain fresh additives, to refresh some of the depleted additives already used by the engine. Amsoil recommends this when running extended intervals with their oil. Most of the time it is done at the half way point in the oil change interval.

FWIW, I had a UOA done on my oil at one change with Delvac1 at about 6000, and I was told that the oil had more life in it.

:D hello ,y'all i'm new here so i think i'm at the right place

Anyway my 02 D-max occasionally doesnt want to fire right away
It didnt happen very often but I tried pumping the fuel primer which usually
works but I have to wait a few minutes from when I cranked it the first time

would this be fuel drainback ? :help2: do these trucks have lift pumps?


Any help would be great on this annoying issue:mad:

02 d-maxer

I have 21,000 miles on Delvac1. I do have a bypass, but I would bet the oil would show good with or without a bypass at 21,000 miles. Delvac1 is an incredible oil designed for MUCH TOUGHER applications that our Duramaxes. A normal UOA will show the oil is still good at 21,000 without bypass. The limiting factor is probably particle count at 21,000 miles, and UOA will not show this. I can say I did a particle count at 5k miles WITHOUT bypass using a Baldwin filter and the oil was quite clean (particle count wise) and the other levels were close to new.

I would have to say Delvac1 with normal oil filter is good atleast to 10k miles or more. I never intended to go this long on an oil change with bypass. I was originally shooting for 10k miles, but my oil analysis was so good I didn't want to throw out a $55 batch of perfectly good oil because it seemed like "it was time". My oil was cleaner at 16,000 miles with a bypass than it was at 5,000 miles without. But with a normal filter, especially a Mobil1, you are good till 10k miles and don't bother changing the filter. That is one great filter with very long life. SPICER

I have 21,000 miles on Delvac1. I do have a bypass, but I would bet the oil would show good with or without a bypass at 21,000 miles. Delvac1 is an incredible oil designed for MUCH TOUGHER applications that our Duramaxes. A normal UOA will show the oil is still good at 21,000 without bypass. The limiting factor is probably particle count at 21,000 miles, and UOA will not show this. I can say I did a particle count at 5k miles WITHOUT bypass using a Baldwin filter and the oil was quite clean (particle count wise) and the other levels were close to new.

I would have to say Delvac1 with normal oil filter is good atleast to 10k miles or more. I never intended to go this long on an oil change with bypass. I was originally shooting for 10k miles, but my oil analysis was so good I didn't want to throw out a $55 batch of perfectly good oil because it seemed like "it was time". My oil was cleaner at 16,000 miles with a bypass than it was at 5,000 miles without. But with a normal filter, especially a Mobil1, you are good till 10k miles and don't bother changing the filter. That is one great filter with very long life. SPICER
What Mobil1 filter fits our trucks? I've never found a listing for the DMax...

M1-303, I believe.

Yes the M1-303 is what fits our trucks. I picked some up but waited until my stock of Baldwin's was depleted(which is a great filter as well).

Anyhow Spicer we'll have to hook up again soon, I'm interested in hearing how your tow went with your new camper.

Thanks! They're priced about the same as the AC Delcos at the stealer, are more widley available, and SEEM to be an Excelent filter. On that thought, is there a Mobil 1 filter that will work an the Allison?

no trans rated filter that I know of. Then again I've never heard much good, bad or indifferent about the stock allison or baldwins for either, I've used the Baldwins but recently replenished my stock with actual allison filters.

Victory Red, for some reason, diesel engines are a lot less predictable than gas engines. I have a customer who had a 7.3L diesel and he had 60,000 miles on the oil without a bypass filter and the last analysis said "no corrective action required. Oil is fit for further use". We did oil analysis regular intervals in order to determine just how far he could go on the oil. Unfortunately he sold the truck before we could find out just how far the oil would go.

Here's what we did find. The analysis will come back occasionally telling you to change the spin on filter and top off. The analysis company told me they do this when they see the oxidation and nitration number start to climb. By changing the spin on filter you will have to add extra oil to top off and this props up the additive package and makes the oil fit for further use. If the oxidation and nitration numbers are okay (not climbing towards 100%) they may not even recommend changing the filter. They also look at the TBN to see if the oil can still fight the effects of acidity, plus the amount of soot in the oil.

You are using good filters and that is important. Your best filters will have a combination of three types of filtration. Cellulose, Glass, and Synthetic media. Filters with this type of filtration have much greater capacity for holding dirt while still providing good oil flow. Cheaper cellulose filters are basically surface type filters that plug up quickly and go on bypass (allowing unfiltered oil to circulate in the engine) and unfortunately there isn't an idiot light that goes on to warn you it's happening.

Just continue to use good filters and trust the oil analysis company to help you make an informed decision about changing your oil. Once you get some confidence you can try different oils to find out what works best for you.

Most of the time our engines are working just as they're supposed to and the oil will do it's job. Occasionally analysis will uncover an engine with a plugged EGR system, bad injectors, etc., and the oil may be used up. At least you'll know what repairs to make, and hopefully before something catastrophic happens.

I hope this makes a little sense. Sometimes my mind works faster than I can type and things get messed up. If I've confused you in any way please don't hesitate to say so.

I've been doing this for my customers for 24 years. It works.

Lynn

I usually run 5,000 on M1 with an M1 filter. I often tow my fifth wheel with the truck and at 5,000 the oil "looks" real dirty. I know thats not scientific but I wanted to ask you guys if you tow fairly heavy loads during these longer change intervals. I was thinking I may be picking up more soot due to towing. Anyone run UOA's under those conditions?

On the upside I've got an early 03 so not CAT/EGR on my truck from the factory, so none of the crap is recycled into my engine like the later years or the LLY's.