Oil Changes on your DIESEL trucks

[Rob & Cathy]

But why does GM put that gauge in their trucks?

What does it measure and how does it do it?

Rob

[Traveler II]

It tells you the percent of oil life you have, i.e., you start at a 100% and as you drive it works it's way down to 0%. I've been surprised how far you can drive before you need to change the oil. I normally change it from 25-40%. I just changed it at 30%, we are getting ready for our winter travels.

I'm not sure how it works, or does it consider the type of driving you do.

[Rob & Cathy]

It tells you the percent of oil life you have, i.e., you start at a 100% and as you drive it works it's way down to 0%. I'm not sure how it works, or does it consider the type of driving you do.

I wonder if it's just based on mileage and/or time. I had a Honda Accord decades ago that would remind you with green-yellow-red indicators when maintenance was due. As far as I could tell it was based on mileage.

Rob

[Traveler II]

Rob, I guess that’s what I’m wondering how reliable this gauge is. Why would GM put it on if you weren't’ suppose to use it? But after reading all this information on oil changes I’m thinking I better re-think what I’ve been doing. A diesel oil change is expensive, but if I’m doing harm to the engine it’s a cheap insurance policy to change more often.

[WVcampers]

I was in an lubrication seminar presented by the specialists that worked for Union Carbide at the time. So they were not selling oil, only trying to make our equipment last longer. One of the points that was brought up is that the viscosity of the oil changes with use. This is due to the fact that multigrade oil like 5w-30w has manmade made alterations. With the closer tolerances of the new machinery including auto engines the viscosity changed due to the shearing of the polymer links that are created to make a multi viscosity oil. They recommended every 3000 miles. They said that the reason that extended oil change intervals are recommended by the manfacture are so they can meet the strict environmental regulations. Oil use is figured in how green your vehicle is. This said I change as close to 3000 miles as I can.

I also have a friend with a 97 ford diesel with 140,000 miles and is running Amsoil system and the oil has neve been changed. It has never had an engine problem and is still going strong.

[snoking]

If one is real concerned, then run to the number of mile you want and take an oil sample. The report will tell you a lot about what is happening to the engine and oil, help you in setting a good internval to change your oil. Somewhere there is a middle ground between waste and protection of your engine. For most applications it is way beyond 3k, with the new Dodge diesels being an exception. Regen is deluting the oil with diesel fuel, so follow the OIC and change it as indicated, which can be down in the 3k range. Chris

[bigbunkhouse]

I had read that the GM oil life monitor reads multiple items, such as run time, ambient temp, engine temp, rpm and speed and possibly others to calculate the life. The studies and actual testing by agencies such as http://www.polarislabs1.com/oil-analysis.php , have shown oil life to be much longer than the 3k that we think. I have been changing 5k on everything I own forever as well as my father, we have had many 200000 plus mile gas motors and never a failure. My work truck started life towing a 5er then went to our 32ft 5er then to an 18ft car hauler work trailer and also plows, and is at 235k with no issues. Todays oils are better, the engines cleaner, materials superb and if you thing700000 miles is a short life because of 5k oil changes ur nutz

[Chief409]

Or if you want, or need to get engine oil info the old fashioned way, a lab analysis, here's one lab: http://www.blackstone-labs.com/
Sample kits are free, analysis are $25 each.

[bigbunkhouse]

chief, that was the lab I was thinking of I just couldn't remember it! Thanks

[Chief409]

Anything to help. With the cost of diesel engines what they are, I'm going strictly "by the OMG Book", and hope to get many, many Happy Trails Miles. If not I keep all the service paperwork, and have the Extended Engine and Drivetrain Warranty. Oil Analysis at each oil change after 15,000 miles and switching to synthetic oil is something else in the files, and/or to deal with the Service Dept. if a suspicious trend starts.

[campswithcritters]

blackstone lab is reported to be the best, and I follow a lot of diesel engine forums. That being said if anyone needs a quick & cheap test for any reason try looking up Speedco locations near you. They are the quick-lube chain for OTR trucks and can do on site less complete analysis for immediate information.

[rlhedlund]

I follow the DIC for fuel filter and oil. I change the oil filter with the oil. Used oil gets picked up by a free service here at our shop. Rags are cleaned by our uniform service.
85,000 miles in three years. Lots of oil changes. 4-5 times per year.
Also maintain a diesel F-800, a gas F-450 and several PU's.

[PaulandTammy]

Every 6 months or 7500 miles.

[teallen]

My manual says 10,000 for light use or driving, 5000 if you tow or stop and go driving in town. I stick with every 5,000 miles

[Rob & Cathy]

A diesel oil change is expensive, but if I’m doing harm to the engine it’s a cheap insurance policy to change more often.

What do you guys pay for an oil and filter change at the dealer?

Rob