Join Date: Mar 2010
Location: Pittsburgh, Pistolvania
I've gone by the DIC. If you change synth at 3-5K intervals, you might as well be dumping new bottles of the stuff in the trash. Modern oil is much better in its characteristics than oil of 10 to 20 years ago. The detergents are better and the oil doesn't degrade nearly as fast. The old 3/5K intervals were mainly meant for use with older oils such as SAE-30 that didn't have the robust addatives that modern oil does. Most oil change places still adhere to the system primarily because it is good business. They make much more money promoting at least 4 oil changes a year (Or more if you actually drive more than 3K in 3 months of time) than they do promoting doing it only when the OLM says so. It used to be that GM's OLM system was based on milage, but the one in the Cobalt is calculated using a complex forumla that GM has programmed into the car. This formula takes into many variables such as engine RPMs, load, engine temps...etc.
GM Stage II | 2nd Gen Projectors | 5000K Low Beams | 3000K HID Fogs | LED Tails| SS/TC Seats
▲RIP 2007 G5: Totalled 1/26/10▲
Last edited by Nighthawk243; 05-02-2010 at 02:54 PM.