Kamran

Here's a viscosity calculator for oil at a given temp:

http://www.viscopedia.com/calculator...extrapolation/

I know one of the well respected Porsche race mechanics who is a part of their 24 hour endurance race programs. He said earlier on they were noticing many cars would go "almost" the distance and just before the end, blow up engines. This was obviously very frustrating for them after all the efforts. However after they increased the levels of ph/zn in the oil, engines performed a lot more reliably through the entire 24 hours.

OBSSSD

Sorry, but 0W-40 M1 is superior to 5W-30 in every way and this has been well established in other threads on other sites through oil analysis. The only thing about 0W-40 is that it starts to shear back thinner some when run for much higher mileage intervals. So long as you are changing every 6k or less no reason not to run 0W-40. For longer change intervals in warmer climates 10W-30 is just barely thicker than the 5W-30 and is also a better choice the 5W-30. GM has to allow for the customers running cars in some very cold climates when they make blanket recommendations.

I run high mileage 10W40 in my 14' CTS-V, but it has a 416 stroker fully modded at 15psi so it consumes thinner grades too fast under higher boost.

gnharley

Also Spherical Chrome Muffler Bearings , I'm told........

willem wallace

At the Mobil 1 0w-40 price point, knock yourself out. Is available at my local Walmart for just over $5.00 a quart. I am listening!

tzoid9

OK, so I see what you've written above and please forgive me, I'm a little slow with your statement. If 0W40 is so far and away superior to 5W30 in this application (engine, C7 Z06) and with this engine oil weight it shouldn't affect any Federal emissions obligations and with the oil pricing being equal (or close enough)....why hasn't GM Engineering changed the "recommend oil fill" to 0W40? I believe we are talking about a Z06 that is used in the normal, street driving type application....occasionally wrung out on the street, rarely tracked, just normal operation of a 650 HP car (oh boy!). Is your background in automotive engineering or petroleum chemistry/engineering? I'm not setting you up here, I am serious...how can you substantiate the accuracy of your statement? If you can, I'll switch in a heartbeat. I think we should hear what your credentials are, to accept your findings. Thanks!

willem wallace

They don't recommend the 0W-40 because the extra lubricants in the additive package of this particular oil formulation could possibly shorten the life expectancy of the catalytic converters under warranty!

tzoid9

OK, that makes complete sense if the European Corvettes don't have catalytic converters.... or do they? I live in PA, what the hell do I know about Corvettes shipped to Europe or the Middle East, etc!

Kamran

Under ask Tadge section, Answered: Changing Oil for Track thread, Tadge said:

"As for the Mobil 1 0W40, it was not available when we validated these engines and, in its currently available formulation, it also contains more phosphorous and ash than we specify. So, even if we validated the 0W40 for track use, we would still have to recommend reverting to a DEXOS 5W30 for daily street use."

tzoid9

Kamran, thanks very much for taking a moment and providing this information. For me at least, this really does clear up the discussion. It's been my experience over the last 35 years, if a bottom end failure occurs in an engine during the warranty period, one of the first things the manufacturer wants is to have an oil sample taken and analyzed by a certified lab for oil grade/type and viscosity. If the failure is a "lack of lub" failure (which is a "catch all" comment, whether the engine was low on oil or the oil was the wrong spec to properly lubricate the engine, both considered "lack of lub" failures), warranty will typically be denied. I'd rather stay with the manufacturer's published spec, just to be sure of warranty coverage. Thanks!

Kamran

U'r welcome!
Always stay ahead of game by having your oil tested anywhere between 500-1500 miles for a base line and at next oil change. Thereafter test your oil every couple of oil change. Cost is $30 per oil test and gives you a heads up if things are going south. Also if all ok, you have proof to show GM everything was moving along just dandy!

Dabigsnake

Great info here:

http://http://www.speedtalk.com/foru...hp?f=1&t=31363

gnharley

" The Sky is Falling "

BearZ06

Okay, now let's discuss which windshield washer fluid we should use or which car wash soap is GM approved. Sometimes these discussions just get ridiculous.

Sk8Man_

I fretted with all these same concerns at the beginning with my 2015 Z06/Z07 and finally decided on the best answer just before doing my first oil change . . . I installed 10W40 Pennzoil Ultra Platinum!!!

glass slipper

The highlighted is not true, Mobil 1 5W30 has a viscosity rating of 10.6 cSt at 100°C while Mobil 1 10W30 has a viscosity rating of 10.2 cSt at 100°C. At lower temperatures, Mobil 1 5W30 has a slightly lower viscosity than Mobil 1 10W30 relatively speaking...but you want a lower viscosity at lower temperatures so the oil will flow to the critical engine parts quicker, this makes the 5W30 a better choice than 10W30 while 0W30 would be the best.

As a side note, the dexos1 oil specification does not allow any 10W30 to be approved. This makes consideration of 10W30 a moot point as it would void your warranty.

GSpeed

To our knowledge, the oil temperature sensor for the Z06 stops reading at 311. We have never had any warnings, or shut downs due to oil temp like water temp, trans temp, or blower pump throttle shut down.

djnice

Gspeed, what your thoughts on the best oil to run street verse track?

GSpeed

Best oil, GM warranty aside? There are several. We like motul 300V due to the base stock, and the detergents it has, keeps everything clean, yet well protected. Redline is a great oil, so is Driven/Gibbs, and Brad penn.

There are several other oils as well, but those are the 4 that come to mind.

Oil choice is just an opinion, when youre dealing with these oils. They are all good, for sure.

DoctorV8

I did. '15 Z07 7 speed, 1400 miles, stock everything, 5W-20 oil. Sold it in favor of a new ACR for track use.

davester

Probably old news, but instead of paying $9.40 per quart for 15-50 Mobile 1 I ordered on line from Walmart in 5 gal jugs. A little over $25 per jug. This will be the third year of track events on my 2015. It goes in for fluid changes, pads, and short shifter install Friday. Love these cars!