jvp

The original question is here.

slickstick

I like this response in some ways and in others I don't. First, my owners manual does NOT have the best information about my car. Yes, I could use what is in the manual but the Mobil 1 0W-40 Dexos 2 didn't exist in 2015 so it's not printed in the manual. Pretty unique/rare situation for a manufacturer to change recommend oil during a car's life I would imagine which causes this confusion. No complaints, having this combined street/track approved oil was a big improvement for anybody who tracks the car at times.

With that said, Tadge doesn't really answer the question regarding warranty. So, I would suspect anybody who is worried about keeping their engine warranty should stick with what is in the manual or covered by tech bulletin. I couldn't find that tech bulletin again after a quick search, but I am guessing it calls out Mobil 1 specifically for the 0W-40 Dexos 2 which is what raised this question. However, for the other oil weights the Mobil 1 isn't required as long as it meets the dexos spec so that would actually be kind of a GM deviation from guidance. One difference being, there is no point in using this oil unless you are tracking the car so they might not want to honor track use with anything other than Mobil 1, period.

In other ways, I like this response because it all comes down to testing. They could never and would never test all possible oil combinations and nobody who designed any kind of product is going to endorse their support or guarantee an untested configuration as a blanket statement.

The HACK

Actually, if I were to read between the lines:

These are approved to use if they meet the weight specs, as GM has confidence in these meeting or exceeding the DEXOS standards?

atljar

I think he was trying to make a point between Dexos spec, and Dexos approved. Dexos spec being the manufacture of the oil says it meets GM requirements but it hasnt been GM verified. Dexos approved meaning GM says it meets their requirements.

If it is GM approved, the link provided, and the correct weight, then you wont have warranty issues

Crossed Flags Fan

"For the LT1 and LT4 engines only, if a 0W-40 Dexos 2 engine oil like Mobil 1 ESP is not available, a SAE 5W-30 Dexos1 Gen 2 engine oil may be used for street use above 45F."
Soooooo If I've been using the recommended 5-30 in my 2014 LT1 since new where the early morning temp is below 45 degrees about 5 months of the year, I guess I can expect engine wear or other issues just about when the warranty runs out.
Nice to know Tadge..........

atljar

Dont hyperventilate, you and the car will be fine. Thinking there is a massive or major appreciable difference between a 5w or 0w at 45 degrees is laughable

vader86

Pretty common sense answer to me. Just better have GM approved oil for your year engine in there if your engine blows.

Patman

What I'm curious about (and I am rather confident I'll be ok) is if GM would approve of my using Mobil 1 5w30 ESP Formula in my 2018 instead? It is dexos2 certified, like the 0w40 ESP Formula, but the 2019 manual recommends a 0w40 dexos2 oil and my 2018 manual recommends a 5w30 dexos1 oil. So the 5w30 version of ESP Formula partially covers both of those manual's requirements. (FWIW, 5w30 ESP Formula has now been replaced by a new formula simply called 5w30 ESP, although I have 5 oil changes worth of the older formula and will probably buy up more of it as I have been buying it on clearance at a lot of Canadian Tire locations up here)

Patman

It's true, there really isn't a big difference between a 0w oil and a 5w oil until it gets extremely cold (way way below 0F) In previous winters here I was running Mobil 1 0w20 in my 2006 Honda Civic, but last summer I switched over to Pennzoil Ultra Platinum 5w20 instead and even on a few -7F mornings here this winter my engine started up just the same as it did with the 0w20 (and with a 7 year old battery no less!) It will be interesting to see the oil analysis results, I'm confident that engine wear will be similar to what I have seen with 0w20 in the past.

Without a doubt, at the temps that 99.9% of Corvette owners will see, they won't get any cold start benefit having a 0w oil over a 5w, as the 5w oil will still flow the same. The biggest benefit in my mind to running either 5w30 ESP Formula (or the new version) or 0w40 ESP Formula is the fact that by being dexos2, it has an HTHS value of 3.5 or more, compared to regular Mobil 1 5w30 which is only 3.1. That means at higher oil temperatures the dexos2 oils will not be as thin as a dexos1 oil would be (a typical HTHS value for a dexos1 5w30 is only 3.0 to 3.1)

KCV

I found Tadge’s “above 45F” statement curious. I will have to reread my owner’s manual because I don’t recall it having that restriction. Odd.

Patman

That is an odd thing to say, because 5w30 has been ok for the Corvette for 30+ years now and all of a sudden it's not good below 45F? Even at temps well below 0F it'll be fine.

Axelrod

Blackstone oil analysis. Is there an ongoing thread anywhere with data? Any owners sharing results?

Patman

This was my most recent oil analysis on my C7:

Mobil 1 ESP Formula 5w30
Fram Ultra oil filter (XG10060)
5,578 miles on oil
Apr 29 to Oct 16 (5.5 months)
8,719 miles total
241.7 total engine hours
25.6 MPG average for this OCI
7 quart oil capacity
No make up oil


Iron 24
Lead 2
Aluminum 3
Copper 19
Chromium 1
Tin 2
Nickel 0
Silver 0
Vanadium 0

Silicon 40
Potassium 2
Sodium 6

Moly 81
Boron 99
Calcium 1032
Magnesium 121
Manganese 1
Titanium 0

Phosphorus 615
Zinc 753

Soot 0
Glycol 0
Water 0
Fuel <1%


Viscosity at 100c 10.8

Axelrod

Any comments from Blackstone about averages? Did any one category stand out as being high for that motor?

Patman

I get my oil analysis from Wearcheck Canada (their lab is only 5 minutes from my work) so they don't make specific comments on wear metals, they usually just comment on the condition of the oil itself (for example: if the fuel dilution level is a bit high or if viscosity has dropped)

Given the fact that my engine is fresh and is still breaking in, those wear metals are pretty much in line with where they should be at this point. In another 10 to 20k the iron level will probably drop to about half of where it is on this report, and same with copper. The other wear metals are already pretty good so even if they stay the same I'd be happy.

Axelrod

Agreed, was going to mention the iron. Also, the Magnesium is curious.

Patman

Mobil 1 ESP Formula has a lower level of magnesium than regular Mobil 1 has, it’s nothing to be concerned about actually

AzDave47

Interesting that Tadge used the 45* point. At 45* down to at least 20* and probably lower, the 0W-40 is thicker than the 5W-30. Once you get into minus numbers, then the 0W is thinner. I don't have the specs on this although I have seen it in the past, but my cold startup oil pressure at 30* is higher with 0W-40 than with 5W-30, indicating thicker viscosity at that temp range.

Patman

You are correct, the viscosity at 40C for 0w40 ESP Formula is 69cst, while at that temperature Mobil 1 5w30 is thinner, at 61.7 cst.

AzDave47

Let me clarify, I was talking *F not *C, so even at 20*F, 0W-40 is thicker than 5W-30. 40*C is 100*F+-. Somewhere near or below 0*F the 0W-40 becomes less viscous than 5W-30