With the new 0W-40 Mobil 1 still being mostly vaporware or $$$ I wonder if this might be a decent alternative. Valvoline 5W-40 synth, "for European cars" but Dexos 2 certified. Anyone tried it? Is there anything about this stuff that would contraindicate its use in C7?

 

Any Dexos 1 or 2 oil is approved but you have to make sure the actual oil is Dexos certified rather than "meets Dexos specs" which is just a fancy way of lying.

Just because 4 years later GM is switching to a 0w-40 oil doesn't mean you can't still use Mobil1 5w30. The new Mobil1 0w40 has a different formulation than other 5w40 or 0w40 oils that are currently out so don't get hung up on the change in viscosity.

Just use Mobil1 5w30 until the new 0w40 is available. Especially if you are not tracking the car. GM's reason for making this new oil with Mobil 1 is so that racers don't have to switch oils when going from street to track and back to street.

 

This particular bottle shows the 2 DEXOS logo.

 

I just spoke to Valvoline tech and they confirmed that the Valvoline full synth MST (used to be called Syntech) 5W-40 is DEXOS 2 certified. Looks like this might be a decent option for those of us that don't do a lot of cold starts in the dead of winter. If the Mobil 1 isn't available in a month when I will need an oil change I am going to give it a try. And by "available" I mean I simply will not pay 3x cost for an oil change to get the new M1. Price for the Valvoline is in the normal range for commonly available synth oil. But of course it isn't "designed for Corvettes".

 

^^^

Yep meets the dexos spec but it is ~$7/quart (MSRP ~$15/quart) and as you say does not meet the required weight, either 5-30 or the ESP Mobil 1 0W-40.

Just changed oil in my Grand Sport with Mobil 1 5-30 and paid $2.20/quart after the Mobil 1 rebate for the 10 quarts.

Have been using that Mobil 1 rebate for all charges in my 2014 Z51 and the 500 mile change in my Grand Sport as well as this last change.

When 0W-40 ESP gets to about the same price as other Mobil oils at Walmart and the rebate works, I’ll use it. Of interest Mobile 0-40 for European cars sells for about the same price in 5 quart jugs and the rebate can be used BUT it is not dexos certified.

 

Not the same as the Mobil 1 offerings but it is well within the viscosity ranges of the approved oils. With the high temps these motors run at and because I drive 90% in hot weather I like the idea of the 40 high end viscosity.

 

I started using Mobil 1 in 1974 for my 260Z for an usual reason as suggested by the Datsun service rep to solve a Hitachi SU performance issue. It did.

After reading about its hi temp properties not just holding viscosity at hi temps, I started to use it in my modified Corvair where when driving aggressively the oil reached 325+ F. The oil quickly formed a scum in the oil fill tube, it was breaking down. Mobil 1 solved that issue and I have been using ever since. As I recall that was 10-30.

In a recent aggressive 40 mile drive with the Grand Sport where I used lower gears quite a bit, the oil got to 220F. I don’t Track so even on a 100 degree day expect I won’t get past 240F with aggressive driving. Well within the acceptable performance of 5-30.

Our Forum “oil expert,” LDB, was wondering what Mobil was doing as his experiance was the oil additives that hold viscosity with increasing temp break down with time at temp. He felt Mobil did something different than what has been available for years in the European 0-40. As he noted, if used for tracking, fine but over time will the viscosity hold. FWIW.

 

Upon further review... The DEXOS question for the Valvoline MST 5W-40 isn't totally resolved to my satisfaction. The tech rep says it is DEXOS 2, one website photo shows the DEXOS 2 logo, but others don't. You never know about those pictures, they can just be using some generic stock photos. And the Valvoline website doesn't list all the specs for each part number but rather says a few are DEXOS 1 gen 2 (whatever that means) and the 5W-40 isn't one of them. So, I'll get by on the old reliable Mobil 1 5w-30 DEXOS synthetic until the Mobil 1 0w-40 is available and reasonably priced.

 

If genuinely DEXOS 2 certified (logo on the jugs would do in court, if no qualifiers present), go for it. the law says manufacturers cannot dictate brand.

 

I'm not sure the picture is legitimate. The Amazon web tech making these pages might just use a stock Mobil 1 photo that isn't representative of the product they deliver. I don't trust them. Now if I see it in a store and it has the DEXOS logo, I would try it.

 

Oh dear god... Just stop it...

You all going on and on about this is like people asking if buying a lottery ticket at a Jiffy Mart gave them a better chance of winning that one bought at a circle K...

The chance of ANYONE having an oil related failure due to not using Dexos cert oil is about ZERO. Just like your chance of winning the Mega Millions.

 

 

^^^

The GM dexos spec is not a "marketing gimmick," although for oil manufactures, they MUST pay GM a tribute to say they meet the spec!

Found this from ~2014: At the time of this writing, oil producers that wish to display the dexos™ logo, get to pay GM a fee of $1000.00 per product license. An additional charge of $0.36 per gallon also applies. Believe GM has changed the tribute amount but don't have details.

I blame API and SAE partly for the problem (with no inside info, just a guess.)
Prior to ~2000 Mobil and other oil companies sold what I’ll call a "true synthetic oil" made mostly from man made molecules. These were labeled synthetic. Then Castrol started to call their “highly refined dino oil" (as some call it) just distilled from crude oil-synthetic. Mobil sued them! Mobil lost!

Unfortunately, API (American Petroleum Institute) and SAE (Society of Automotive Engineers) supported Castrol who said performance is the key not a name! Why would they do that? Because SAE and API got a small “tribute” per quart if you put on the containers meets API xxx or SAE xxx specs!

I’m sure SAE and API did not expect GM would develop their own spec and ask for a tribute as well!
Great and only article I found on the subject in Car and Driver magazine: https://www.caranddriver.com/feature...mantics-column

I have been using Mobil 1 from 1974 and it solved the oil breakdown issue I had with my modified Corvair where the oil could reach ~325 F (I installed an oil temp gauge.) However, as the Car and Driver article stated, once "dino oil" could be called synthetic Mobil and other manufactures had to switch as it cost ½ the prior, mostly man-made molecule, product to produce! Prices did drop about in half!

 

Yes, marketing, branding and assorted questionable schemes to protect and add to profits... it's the American way.

I have been using syth for 30 years in my vehicles, not so much worried about breakdown on normal change intervals, but does keep engines a lot cleaner inside. When I changed the cam on my 1994 Camaro at 80k miles I was pleasantly surprised at the cleanliness of the insides. Used to buy Mobil 1, Castrol, Pennzoil, or Valvoline depending on what was on the "oil change special" sale at the time. Now Mobil 1 availability at WalMart and Amazon along with the annual discount rebates make those sales a moot point.

Just visited local Advance Auto and they had the Valvoline 5W-40 on the shelf and it does have the dexos 2 logo so I may give it a try. Problem is it is $9.99 there per bottle and no 5 qt/l size available. Amazon has it for $6.97 per small bottle as an add-on item that must ship with another order greater than $25... probably limited to one bottle at a time? They also have 6 bottle cases for $62 Prime.

Also found in stock at local WalMart for $6.97.

Just another data point... YM&OMV.

 

In my 2016 z51 i have run the mobil one 0w40 European since the first 500 mile change . Dealer serviced and installed . I also use this oil in Porsche , Acura and Toyota . If Porsche and Mercedes puts it in there cars it can sure run well in a small block GM V8 . dk.

 

I also like that idea but I would prefer the lower end 5W to the 0W. 5W has been plenty thin enough for winters, especially since I rarely drive then, and plenty thin enough for cold starts. But I won't to pay a huge premium for it.

 

Another alternative to the M1 0w40 ESP is M1 5w30 ESP, that's what I'm running in my C7 actually. On paper it has better technical data than the 0w40, it's HTHS is slightly higher (3.58 vs 3.55), it's flashpoint is 20 degrees C higher, and it's got a lower sulphated ash number (0.6 vs 0.8) It might start out slightly thinner (12.1 cst at 100c vs 12.9) but because it uses less viscosity index improvers, it should hold it's viscosity much better as it gets more miles on it. And yes, it does have the dexos2 certification.

I decided to try this oil out because the 0w40 ESP isn't anticipated in stores until late summer/early fall but I think I might just continue running this oil even after the 0w40 comes out. The one big negative is it's cost, it's still quite expensive in most places, around $11 or $12 per quart although I've heard a few people on other sites mention they found it locally for as low as $8 a quart (still not as good of a price as M1 5w30 from Walmart in the 5 quart jugs mind you)

I'm only 1100 miles into my first run with this oil but so far what I like a lot is the idle oil pressure is higher than M1 5w30, even when the oil gets a bit hotter, so this shows it's maintaining a thicker viscosity. Great news if you like to drive hard from time to time.

 

The product information sheet clearly shows Dexos 2

PI_SynPower-MST-C3-5W-40_047-04.pdf

 

Good find. The general info web page listed several weights of the MST oil that were dexos but omitted the 5w-40.

 

I agree. Sometimes you just want to reach out and slap them and say "Snap out of it!"
I actually use Valvoline Synpower 5w30 in ALL my cars and none have imploded yet.