There are many threads about the high oil useage of our Z's, some using a quart in as little as 800 miles. Many of them are using Mobil 1 and other synthetics. When I first got my 2003 Z, it had 54000 miles on it and about 400 on a Mobil 1 10W30 oil change. In another few hundred miles, it was down a quart. Having always used high quality 20W50 in my 5 other Z's, I put in a quart of that weight, non-synthetic. In about 1000 miles, I was down another quart. Put in another quart of 20W50. Now have another 1000 miles and guess what. Not a drop down. 40% of what is in there now is non-synthetic 20W50. Could the high oil useage on mine and others have something to do with using synthetics or perhaps the lightness of the 10W30? BTW, there were major problems with Mobil 1 in aircraft engines several years ago and it was pulled out of that market.

 

Synthetic oils do burn more than regular oils. I am testing out redline oils on my car, because I would burn a lot with royal purple.

 

synthetic oil is a complete waste of money imo...i switched back to dyno oil in my Z last year.

 

That's a myth.

Uhh...Redline is a synthetic.

bill

 

Run two engines for 100,000 miles, one with synthetic, one with regular dyno oil, then tear them apart. You'll change your tune.

 

I've used strictly Mobil 1 in my last two vehicles. Never any probs. or oil consumption.

The only way that I could see oil consumption is through old leaky gaskets. Synthetic oil molecules are homogeneous and conventional oil molecules vary in size so that if a microscopic leak forms the larger molecules from the conventional oil could possibly clog or block the leak before it starts. While the smaller uniform molecules of synthetic oils don't have ununiform larger molecules in the mix to do this. Either way the oil isn't the problem, gaskets need to be changed from time to time.

 

Mobil 1 10w30 in my car for 70k miles. I lose, AT MOST, 1/2 quart IN 3500 MILES...

 

There was a website (dont remember where I can find it), but it tested about 300K miles on NYC cabs on different oils including dino and synthetic and no conclusive difference was found when engines were torn apart. Can you explain that?

 

Regular dyno oil will leave a slight varnish on all your internals over time is what I mean.

 

I know redline is synthetic, so is royal purple buddy. I was trying to say I was burning more oil running royal purple than I am running redline.

 

My car eats dino and synthetic....

 

Ahhh...got it.

bill

 

Other members report less burning with Royal Purple, explain that.

 

Give me a good bourbon, like Wellers. It doesn't burn near as bad as that Royal Purple Poo.

 

All those that claim to be burning oil need to check thier from main seal for leaks. Just some helpful advice.

 

IMHO if synthetic oils were no better than regular dynos, they wouldn't have been used in racing cars.

 

How much are you burning with the Redline? I am burning some Royal Purple. I have some Amsoil on the shelf i'm going to try next.

 

after replacing my rear main seal I loose ZERO oil and I run nothing but Royal Purple's Race Oils.

 

Yep. I have RP in the diff and tranny and my Z loves it.

 

Though I do run synthetic, NA cars will be just fine on a simple petroleum base like Castrol 10w30.