Well I've been wondering about this for a while. I run Mobil 1 in my Z and have in the past changed the filter and added ~1qt @ 5K mi, then change it all at 10K mi.

Now, I have 13K mi on the oil and am about to change the filter again here soon in 2K mi... I looked at it and it's still a medium to dark brown, not black at all.

Would it be safe to push it to 20K mi changing the filter and adding a quart every 5K mi? Or is that a big

The vehicle still runs strong and all...

Input is appreciated...

 

i wouldn't even think about running mobil 1 oil that long...it's almost always dirty after about 3500 miles. running it 13k is insane in my opinion. AMSOIL says their oil is good to 7500 miles and they're the only one i've seen that says they are good to over 3k, i typically run my truck with 15/50 M1 and go 3k-4k and i put M1 10/30 in the Z28 and have almost 1500 on it and it's clean as hell. the 15/50 that went into the truck when the new setup was done only has about 70-100 miles on it and it's already dirty as 3k mile dinosaur oil would be. gotta get that taken care of actually.

 

I try to never go past 4k without a new filter and oil

 

i think the new vette standards would be a good guideline.

someone correct me if i have this wrong but don't they use mobil 1 and recomend changes at 10,000miles?

 

http://neptune.spacebears.com/cars/stories/mobil1.html

Here is a write up on some guys who put it to the test. They got 18k out of it and if I remember right, they said it was prolly good for a little longer.

THey also are testing AmsOil, and are only 8k into it so far.

 

hmm, just found this on the GM page

Up to 15,000 miles or 1 year. Maintenance needs vary with different uses and driving conditions. See the Owner's Manual for more information.

i would go 15,000 unless you see harsh conditions like all in town driving.

 

what weight syn oil do you guys run? i might start going a little further on mine if you guys are in the same ballpark for weight.

 

10-30 here

 

The guys on that oil test said if you changed the oil filter and added a quart of M1 every 10k, they didnt know how long it would last, said it was fairly indefinite. It was a very good read.

 

I use M1 10-30 or 15-50 depending on what time of year it is. I put it in, check it about every 2500 miles, and change it at 10k. I used to do that filter and add a quart thing, but IMO that is a waste. My uncle bought a new toyota van a few years ago and he changes it every 15k and had over 240,000 on the clock the last time I saw him with no engine probs so far.

Oil change intervals depend on a lot of variables like driving conditions, length of trip, condition of the engine, etc