engine trans oil question

going to open a big debate, probably, if my experiences on motorcycle forums is anything to go by....
recommendations for which engine oil to use here in England. Also while at it, Transmission oil
Make rather than viscosity, and available here.

Firstly perhaps start with what period of engine do you want to discuss - what is suitable for a 60's, 70's and perhaps early 80's wont be applicable to a later engine where synthetics will be the norm, yet perhaps a waste on money on the earlier cars.

You did not mention the year or which tranny but
I have used since all the C4s I had and my C5 Mobil I
for engine, manual tranny and rear end
Their ATF fluid works for both auto and manual trannies

That works well even for high speed long distance racing, even in hot weather
GM also uses these for their race vehicles

C4s were required to use Mobil I for engine oil
Best for all three is Mobil I synthetic
If engine has lots of miles, Mobil I have a high mileage synthetic version

as its posted in the C4 section , thought obvious.
1987 5.2 Ally heads and auto trans. 95k miles.
Its been sat on a drive for last 9 years with occasional starting.
my previous questions are all as a result of it standing.
Mobil 1 then

purple charlie said:

as its posted in the C4 section , thought obvious.
1987 5.2 Ally heads and auto trans. 95k miles.
Its been sat on a drive for last 9 years with occasional starting.
my previous questions are all as a result of it standing.
Mobil 1 then

Click to expand...

Don't use normal Mobile 1 as it hasn't got the ZDDP that flat tappet engine requires.
You need a high ZDDP (zink) oil, Driven HR2 (mineral oil) or Driven HR4 (synthetic) are both designed for flat tappet cams, or Lucas Hot rod and classic motor oil.
Transmission you need Dextron 6 (Dextron oil is backwards compatible)
Rear dif is 75 - 90 with the correct AC Delco LDS additive.

ok, thanks

Steven Smith said:

Don't use normal Mobile 1 as it hasn't got the ZDDP that flat tappet engine requires.

Click to expand...

If I remember correctly, it used to be said on here that Mobil 1 on sale here is not the same as Mobil 1 in the US. And Keith at Eurovettes used to import it from the States for us.

GM's first makeup standard was labeled dexos1
Then next version was dexos2
Newest version and required for Corvettes is dexosR is is backward compatible to versions 1 and 2

Europe required more cleaners and is labeled dexosD as more diesel engines there
Also, labeled as dexos ESP

GM dexos website as this shows what versions are newer but can be used with older versions as are backward compatible
Website shows for each version what vendors are approved and their license number

GM dexos

Mobil 1's website shows all types

Use this webpage, enter your year, model, and it suggests which Mobil I to use


As side note :

When I worked for GM engineering in Warren, Mi I had a testlab in the underground of manufacturing B building
Few labs down from mine was Mobil 1 and they for many years there do testing to assure as new GM products are made
Mobil 1 works with engineering to assure the makeup of oil works well with the new engine designs and were involved with GM's makeup of dexos versions