My Change Engine Oil message finally displayed for the first time at 6,439 miles. Good thing I didn't wait for it and changed the factory oil at 3k. I have to wonder what the validity of such a system is and how accurate it is regarding the health of the oil. Since I replaced the original oil with Mobil 1, maybe it will be more usefull for the change intervals for a synthetic oil.

 

I put Mobil 1 in around 2500 miles and I'm now going to use the change interval the computer monitors. When it reaches 0%, I'm going to swap out the Mobil 1 oil/filter. I'm figuring around 6500 mile change intervals as well, which for a low rpm truck engine, the Mobil 1 should still be in superb shape.

 

I completely rely on it... It monitors a number of parameters. Maybe up to 6 or so? Outside temp, engine coolant temp, rpm, etc. etc.

My winter oil-change intervals are at 4K miles, my summer ones seems to be just over 6K.

I feel strongly that GM wouldn't put one of these systems in the truck if it wasn't giving proper information. Sure, most damage would be found after the truck was out of waranty...... but can you imagine all of the angry people not buying GM's ever again because of lubrication issues? Look at the "Dodge and the bad trannies" stink that's still going around. I don't think GM wants any of that.

 

For those running M1, I suggest doing a search up in the Internal section on the site.

A lot of people don't recommend the 5w30... too thin for these motors.

 

I live in south Fla, so I went with 10W-30. Should be good for year-round here.

 

Actually, modern mineral based oil is probably good for about 5000 miles. I posted questions about what the best oil is and someone posted a link to a forum that does nothing but talk about oil. They send in samples to laboratories and evidently a good brand dino oil is good for around 5000 miles while synthetics are good for around 10000 miles (with a filter change). You could probably push each a little further. In Europe they have really extended drain intervals and they get away with it. At any rate, 3000 mile oil changes are BS, unless you live in an incredibly dusty environment and run the **** out of the vehicle.

 

M1 5W-30 is factory fill on my Vette. Also, having logged over 4,000 miles already on my M1 5W-30 oil change in the truck, it hasn't burned a DROP of oil.

How is it too thin again?

 

i was under the impression thinner oil, pumps faster, dissipates heat easier and causes less parasitic friction. there was some discussion about the oil not pumping up fast enough on start up, and motors sounding like diesels. i actually found a case of m1 0-30 here and ran it for 5k. my motor was quieter on startup and there did'nt seem to be any negatives. the only reason i went back to 5-30 was the oil change places out here don't stock the other and i really don't like doing it myself. guess i'll have to read up on that, what are the downsides of running thinner oil as long as the heat index is acceptable ? i mean besides more tendancy for leaks in an old worn engine. e

 

You're probably right, but the point I was trying to make was that this was the first time the message was displayed and had I waited until it was, I would have run the original factory oil for more than 6k. Although modern engines don't require the extensive break-in that engines used to require, I would still be uncomfortable running original oil for more than 3k due to the possibility of contamination with fine metal particles from parts such as rings and bearings during the seating processes. It seems that the owner's manual should address this unless GM just doesn't feel that it is an issue any longer. The oil change message interval may be appropriate for all after the first change, and I'll still use it as a reminder for my synthetic change, if it continues at about the same interval.

I have long used 10W-30 synthetic in my boat engines, which are twin inboards. Marine engines operate in a harsh environment, running at higher RPMs for long periods in a very hot engine room. My oil analysis results always come back satisfactory with very little contamination in the oil. When I originally ran Valvoline dinosaur oil, my analysis would always come back with indications of metals from bearings, not abnormal, but much higher than the results with synthetic. The change interval for my boat engines is every 100 hours. By comparison, for what it's worth, the hour meter on my truck showed 242 hours when the change oil message was displayed.

 

I use M1 5w-30 in my Sierra...changed orig. oil 1t 3,084 mi. I have a 93 Civic with 202k that still runs fine (same M1) . I used it in a 86 G10 with a 305 until I sold with about 130k..it still seemed to run like new. Had a 78 G10 with a 250...used it in that (5w-20 back then) but too thin..had to add a qt about every 2 wks...went back to reg.