US spec oil Mobil 1 5w-30 dexos 1

maudyz28

Regular user
Hi all, i've looked and really cannot find any in my usual places.
My car is a US C7. Definitely since ~12000miles its been changed on mobil 1 5w-30 dexos 1 spec US. The guy I bought from was US military in DE (where I live usually), so he had everything on base. I'm not coming up to 48000miles and the second service with me. Prev owner gave me 10l oil upon purchase, but now I need to change and can do it easier (as i'm currently in the UK). Where can I get this from, I don't think the Mobil 1 ESP is 'exactly' the same in terms of spec. And i've had a bad experience changing oil brand before in my Camaro. Maybe just my superstition, but I prefer to keep what it 'likes'
 

Stingray

CCCUK Member
Mobil 1 5W-30 ESP Dexos 2 currently £50 at Opie Oils (online seller).

Mobil 1 0W-40 Dexos 2 currently £50 at Halfords (reduced from £62).

Depending on the year of your car and assuming it's a dry sump Z51 (as opposed to base US car) you may need to watch out for over-filling when you put the new oil in. Some early Z51s have an incorrect reading on the oil tank dipstick. i.e. When it reads "full" it actually means "a bit too full".
 

maudyz28

Regular user
Thanks for this, yeah its a Z51.
But still these are both ESP EU oils.....the car has only 'ever' seen the official 5w30 US Dexos 1 spec.
I've tried but cannot find full spec lists on contents etc, and its even more confusing as EU is advised to run 0w40 ESP...but now 5w30 ESP is available....
 

Rich

Administrator
In Europe, GM recommends Dexos 2. I get mine from the local Vauxhall dealer. Same engine as yours in my Camaro. GM branded oil - used it for years.
 

maudyz28

Regular user
Hi Rich, indeed this I used to use in the LS1 camaro, but since the head/cam etc it was not happy at all. Used to eat it, so I swapped to shell (which I used on and off before) - and it likes much better. Or at least doesnt eat the stuff. That got 1/4 miled a lot, and OE was not suitable really.

For the C7, i'd be happy to keep the same spec. Bear in mind, I will be back to DE, and the autobahns have no speed limit, it will be sat at higher speeds for longer periods than would be normal in UK.
 

teamzr1

Supporting vendor
dexos 2 was designed with a makeup to deal with diesel engine exhaust makeup which is more common in Europe
where dexos 1 for gas engines.
I suggest using what GM states

As working for GM engineering at the Tech center in Warren MI I had a testlab, few labs down was one Mobil I have and
is always doing long term testing to assure their oils meet the engineering specs required
They test long term to see if their products work well with anything from gaskets, O-rings, internal of engine, etc

That also means they are getting a lot more tech detail directly from GM where others are kinda guessing

I got wacked good by not sticking with Mobil I
When my 1994 ZR-1 was almost new, the owner of Redline oil came to me wanting me to use their engine oil and tranny fluid
as all my racing, he wanted to market Redline via my racing

I talked to him multi times and asked him if he was sure his products complied to GM specs, which he stated it would and
would NOT cause a void of GM warranty

Sure as shit I replaced engine and tranny with Redline and very first race the Redline engine oil was leaking via valve covers
even pulling upwards to cover bolts
The MN6 syncros fouled up and made shifting hard

Took the ZR-1 to dealer I bought it from and when GM saw the red color or oil and tranny fluid they voided the ZR-1 warranty
Asshole of Redline would not stand up to what he promised me, so I was a real loser in not sticking with GM requirements

Cost me $5,000 GM charged me to replace the MN6 :(
And due to Redline engine oil one lifter in LT5 engine was collapsed, and I had to pay for that repair also :(
 

Rich

Administrator
dexos 2 was designed with a makeup to deal with diesel engine exhaust makeup which is more common in Europe
where dexos 1 for gas engines.
I suggest using what GM states
There is a post here which clarifies Dexos 2 in Europe.

 

Stingray

CCCUK Member
Both of the oils I mentioned above are fine in a Vette.

I've been using them more or less interchangeably in my Vettes for the last 25 years and the engines haven't exploded yet. Modern motor oils are incredibly good at their job.
 

maudyz28

Regular user
teamzr1 - thanks for sharing, this has been my experince with some other oils. Interesting about the gearbox. The prev owner put royal purple in the M7 trans and it made the 1-2 notchyness worse, redline has improved this. Again, maybe I'd have gone with GM, but its either impossible, or 'annoyingly' expensive to try get it from a dealer (e.g rock auto $4 a quart, GM DE 25 euro + (why?)

Stingray, can I ask what kind of driving you do, any track, how 'spirited? If the ESP is working great then that makes me a bit more relaxed, as said, the C7 does get blasted on the autobahn sometimes.

I'd like to know the additives etc or how they all measure up. I know I can get into a deep hole opening this convo...
 

Yellowshark

Well-known user
FWIW I have used the GM (probably Europe) recommended Mobil 1 0-40 in my C5 for 21 years and 165,000 miles without problem.
 

teamzr1

Supporting vendor
Mobil I does not have to be your choice of engine oil if vehicle is under GM warranty

It can be any oil seller that has a dexos license number from GM as meeting
dexos1 gen 2
dexos1 gen 3
dexos 2
Go to the GM dexos website below and then click on each of the above, and it will list the vendors brands

GM dexdos
 
Top