1st oil change

[TLightning]

The reason the mechanics recommend changing the oil at 3k intervals is to make a buck. As noted earlier GM recommends 10k/annually/or when the DIC says do it. All vehicles have gone to much longer intervals now. The DW's Acura has the same thing as GM's DIC, it works out to about 7,500 miles for oil/filter changes.

[bigmurf]

Once a year for the oil. 5000 for the filter. Samples every 10,000.

[TAKPAK]

I personally use the DIC on my 2008 GMC Duramax. Just took it in to the dealer for it's first oil change (free) at 6500 miles/six months (35% oil life left.) Grilled the dealer about it and he said follow the DIC. It monitors engine temps, driving conditions/style, speed, load, etc, and makes a "life" decision based on multiple factors. After reading many articles in trade magazines about it, the concensus for oil changes is how the vehicle is driven, not so much the miles. Long hauls, short trips, all factor in.

That said, now a question that ought to get some interesting responses; has anyone started using a synthetic oil in their rig? Again reading many trade articles, the argument for/against rages on. Interestingly enough, most of the articles I've read are against using synthetic, EXCEPT in rare and extreme cases, such as mining equipment in the Andes, construction equipment in the desert, or something like that.

[8.1al]

After I started using synthetic in my race car and say the remarkable difference it made in the condition of the engine I became a believer in synthetic. I can't imagine why any article would discourage it's use. If you are only going to keep the vehicle a few years I guess it would be a waste of money, otherwise I think it's money well spent

[TLightning]

GM says it's okay to use synthetic, but the mileage between oil changes does not change.

[cucalene]

The new blend of oils today do not need 3,000 mile changes you are wasting money. The CJ-4 oil is a big improvement over the past oils. Oil compamies are coming out with synthetics for diesel that should go 10,000 miles or more. The best way to tell how well your oil works do an oil sample. The only times you might needoil changes sooner is if you are using high concentrates of Bio-diesel. Testing is being done to see how much it breaks down engine oil.