[Stephen12ZL1]

5w30 street & 5w40 track use and no oil usage thus far

[Badmojo]

Originally Posted by unavailablezl1

I have 4700 miles on the ZL1 and had the oil changed at 1700. I wanted to report for comparison: so for 3000 miles since the oil being changed the car burned 1.75 quarts. I don't baby it but don't redline it(much) and drive it fairly hard. Do you think is an acceptable amount of oil?

If the oil is cold, it takes up to 2 hours to properly register on the dipstick. How did you measure 1.75 low?

It takes a long time for the oil to drain out cold.

[cwebster]

Originally Posted by unavailablezl1

I have 4700 miles on the ZL1 and had the oil changed at 1700. I wanted to report for comparison: so for 3000 miles since the oil being changed the car burned 1.75 quarts. I don't baby it but don't redline it(much) and drive it fairly hard. Do you think is an acceptable amount of oil?

Originally Posted by Lashu74

I've been burning through it as well, about the same amount as op. I thought maybe using the Mobil 1 would help. My service shop claimed they were able to do my second change with the Mobil 1 but who's knows if they actually did. I was low after 1000 miles and first oil change. I was low on 2nd oil change and now I'm about half way through the life of what was supposedly Mobil 1 and its reading all the way at the bottom of the dip stick. It was definitely full when changed I checked it. I've been told that it's normal for these engines but this seems kind of excessive. I also get a nice cloud of black smoke out the exhaust when I get on it. It only seems to happen when I've been cruising a while and then get on it. I guess just burning off the build up?

I've had my ZL1 M6 for 15 months now. Not my daily driver... 98% of the miles are to/from/at the drag strip or track. I check oil and everything else before each track day. I've never had to add oil except after an oil change. The car is at 5900 miles and I'm getting ready for my 6th (maybe 7th) engine oil change.

You guys should not be using that much oil. If you're using that much oil, especially if you see bursts of bluish smoke when you mash the gas, your piston rings may not have seated properly during break-in. It's also possible you have a clogged or malfunctioning PCV valve, resulting in excessive pressure build-up in the crankcase. I would expect the ECM to throw a code if this were the case, though.

If you're truly getting dark black smoke that's a separate problem. It's most likely from un-burned fuel. Look for clogged air filter or fuel system restrictions.

The viscosity of the oil will not have a measurable effect on the amount of oil you burn. When your engine is warmed up 40 weight oil will get sucked past the rings almost as easily as 30 weight if they're not seated.

--Cal

[CT ZL1]

Originally Posted by unavailablezl1

I know when I had the GT350. I ran it mainly hard to 7000 rpm most of the time. (hey, it revved to 8200) almost 70 percent of shifts. It burned 5 quarts in 2500 miles and now Ford said that was normal after other people got a new motor when they burned that much.

So I did a month long unit test of only driving on the freeway, no high speeds, no high rpms get on and get off the freeway and done. After 1200 miles it did not burn anything measurable. So that proved to me that it is how I was driving it.

So when people say, "not a drop" which of course is a generalization, (it would burn up if it didn't burn anything), then that tells me they are taking it easy and a lot of highway driving and not a lot of shifting, just a thought.

I had the 16 GT350 also and I was adding a qt of oil every 600-700 miles bw that and no trans cooler a big reason why I traded it in the dealer tried to tell me this was normal but some guys were going through alot of oil others not any. As far as the ZL1 only 200 miles on mine so I dont know. Other guys also were trying to draw a correlation bw breaking the engine in easy to using more oil but I dont know if this is true or not

[STAY IN IT]

I broke mine in pretty much by the book and have run it pretty hard since. After the 1500 mile oil change, I added a half quart at 3500 miles. It would be interesting what impact, if any, the break-in has on oil consumption. I would think the driving style would be the biggest factor. As others have noted, running it hard probably translates into higher oil consumption. I blow some smoke every time I do first through third gear pulls, shifting at redline.

I’ve had a number of vehicles in the past use more oil than I would like or expect from new, but they have all been the higher horsepower vehicles. I’ve stopped letting it bother me, unless the consumption is over a quart per thousand miles.

The Z06 forums probably have some good “data” on LT4 oil consumption.

[Stephen12ZL1]

Originally Posted by cwebster

I've had my ZL1 M6 for 15 months now. Not my daily driver... 98% of the miles are to/from/at the drag strip or track. I check oil and everything else before each track day. I've never had to add oil except after an oil change. The car is at 5900 miles and I'm getting ready for my 6th (maybe 7th) engine oil change.

You guys should not be using that much oil. If you're using that much oil, especially if you see bursts of bluish smoke when you mash the gas, your piston rings may not have seated properly during break-in. It's also possible you have a clogged or malfunctioning PCV valve, resulting in excessive pressure build-up in the crankcase. I would expect the ECM to throw a code if this were the case, though.

If you're truly getting dark black smoke that's a separate problem. It's most likely from un-burned fuel. Look for clogged air filter or fuel system restrictions.

The viscosity of the oil will not have a measurable effect on the amount of oil you burn. When your engine is warmed up 40 weight oil will get sucked past the rings almost as easily as 30 weight if they're not seated.

--Cal

I agree with the rings not being seated and this causes excessive blow by. Blow by in turn causes oil consumption. Thinner viscosity oil will blow by easier for obvious reasons. The PCV system doesn’t use a replaceable valve on our ZL1s and would guess this system is not an issue due to the newness and mileage. As stated, if crankcase ventilation were an issue, it would likely trigger a malfunction code. My suggestion is to take it to the track and have some fun with this awesome machine! It may help this seating/sealing process and lessen the oil consumption. GM certainly is not going to consider oil consumption an issue unless it is “off the charts”. One quart per 1000 miles is within their parameters of normal from discussions in the past.

[Gunkk]

1600 mi since the first oil chance and hasn’t used a drop under spirited driving.

[Smudo]

Guys zero, nada, cero OIL !?
Think oil is the blood for the engine, so no consumption, something wrong,
same with too much (sealer)

[6spdhyperblue]

The higher rpm u run the engine the more oil u burn. With paddles and rev match I would bet a lot of ppl engine brake more than ever which eats oil

[cwebster]

Originally Posted by STAY IN IT

I broke mine in pretty much by the book and have run it pretty hard since. After the 1500 mile oil change, I added a half quart at 3500 miles. It would be interesting what impact, if any, the break-in has on oil consumption. I would think the driving style would be the biggest factor. As others have noted, running it hard probably translates into higher oil consumption. I blow some smoke every time I do first through third gear pulls, shifting at redline.

I’ve had a number of vehicles in the past use more oil than I would like or expect from new, but they have all been the higher horsepower vehicles. I’ve stopped letting it bother me, unless the consumption is over a quart per thousand miles.

The Z06 forums probably have some good “data” on LT4 oil consumption.

My break-in was aggressive - not careless "drive it like you stole it" but careful, progressively increasing throttle pressure and cool-downs with sensible precautions from day 1. By 600 miles most of the work was done. By 1500 miles I ran 11.62 ET @122 MPH bone stock. I don't see any smoke whatsoever in any gear at any RPM up to redline and no discernible oil consumption.

You won't get any scientific certainty on any forums as this is always a hot topic with strong opinions on both sides. You will get lots of anecdotes and unqualified opinions. All I can say with certainty is what seems to have worked for me. IMHO, excessive oil consumption and bluish smoke is a classic side-effect from a passive break-in. It's usually accompanied by lower cylinder compression resulting in reduced performance and lower fuel economy. Like most things, people need to do their own research and decide for themselves what's best for them.

--Cal

[unavailablezl1]

Originally Posted by Badmojo

If the oil is cold, it takes up to 2 hours to properly register on the dipstick. How did you measure 1.75 low?

It takes a long time for the oil to drain out cold.

It was low so i kept adding oil slowly until it came up and that is what I added.

[bobby35ny]

changed my oil at 1500 miles. I'm at 8500 miles now. 22% left on the Life meter.
I checked my oil today because of this post. DOWN A QUART at 7k miles.
I do use rev match and drive well over the speed limit.

[mr965]

5k miles. Broken in properly and 95% track miles. Zero oil consumption.

[VAZL1]

Originally Posted by bobby35ny

changed my oil at 1500 miles. I'm at 8500 miles now. 22% left on the Life meter.
I checked my oil today because of this post. DOWN A QUART at 7k miles.
I do use rev match and drive well over the speed limit.

22% on the oil life meter, why do you wait that long?