Oil Usage

[Hib Halverson]

Originally Posted by TealZR1

Yes, like most of us foot is mashed much of the time for the fun of it. The car runs 10 W 30 synthetic. At this point of it's life. Should I run 10W-40 or 20 W 50? Thanks for your help!

"Foot mashed much of the time" means to me that you run the engine hard. If that's the case, with that mileage, I wouldn't worry about 1000 miles per quart.

I'd stick with 10W30 unless you experience sustained high oil temperatures, say...above 250°F. If that's the case, go to a 10W40.

I've had great luck with Gibbs Driven DT40. It's actually a 5W40 and, nowadays, I use it in all my Corvettes.

[TealZR1]

Originally Posted by efnfast

It seems like the first quart goes away very quickly. Leave it down a quart, as long as your not road racing, you should be ok. Don't forget, it has 12 quarts in it.

Thanks Efn, I have a question. If I let the first quart go away and not refill it. Would the remaining oil dissipate also? What happens when that first quart burns off and where does it go? Thanks

[A1990]

Originally Posted by Hib Halverson

"Foot mashed much of the time" means to me that you run the engine hard. If that's the case, with that mileage, I wouldn't worry about 1000 miles per quart.

I'd stick with 10W30 unless you experience sustained high oil temperatures, say...above 250°F. If that's the case, go to a 10W40.

I've had great luck with Gibbs Driven DT40. It's actually a 5W40 and, nowadays, I use it in all my Corvettes.

+1 for Gibbs Driven

[efnfast]

Seems oil consumption drops dramaticaly once the level drops a little. I've heard it referd to as windage from the crank.
My 90 seems to lose a quart real fast, then very little after that. As mentioned earlier, the 90's don't have exhaust valve guide seals (mine will shortly), so the oil goes out the tail pipes. Of course at high rpm, you don't even notice in the exhaust.
One quart out off 12 is only a 8% loss of volume. one quart out of 5 (regular engine) is a 20% loss of oil. -Steve

[Jagdpanzer]

When to the full mark the oil level is right up against the windage tray. So if the oil level is a little over the crank catches it and the overage mostly goes out through the pcv system in a hundred miles or so. As mentioned you can run the oil level down a quart without any risk to the engine however, the low oil level light may become a nag sooner due to its sensor being located more or less at the same position as the windage tray. Unfortunately it's not easy to relocate the sensor a little lower.

[TealZR1]

When I inspected my PCV valves recently I did notice what appeared to be more oil than should be on the valves - my best guess. Hopefully this post helped others like newer ZR1 owners since this appears to be a common issue. Interesting to learn no valve guide seals were installed. My next project I guess down the road so will be back in touch on how to do this project.