The 'E' Type Forum

Hello,

I use in my 2 Jaguar XJ-S V12 + Viper SRT10 Castrol TWS 10W60 synthetic engine oil. After rebuilding my V12 E Type engine, now the question is: should I really go with mineral 20W50 oil to prevent oil leaks or better upgrade with synthetic 10W60 Castrol TWS oil. I mean 10W60 is no ultra modern 0W30 oil that is too liquid and can cause direct oil leaks. But here in Valencia, we have in summer very high temperatures...

Or is a semi synthetic Penrite HPR15 15W60 or Penrite HPR30 20W60 mineral the way to go?

Please tell me all your experienes and ideas concerning the V12 engine.

Thank you and best regards

Carlos

Hello Carlos

not an expert in V12 engine , just sharing my experience :

I am using Castrol GTX High Mileage 15W-40 A3/B3 with great satisfaction (no troubles) for many years now and was indeed advised by my Jag mechanic (more than 25 years expereince with Jaguar cars and E-Types ) not to use 0/30 , 10/60 oils that may be" too liquid" for our V12 engines.

just my 2 cents, hope more V12 owners/experts will comment/give you further advise .

Hello,

you cannot compare directly 0W30 with 10W60. 0W30 is much thinner when cold and 10W60 has much more heat resistance when the outside temperature is very high (for example in july here in Spain) AND the engine is running at high revs... 10W60 was the only approved oil for Alpina B10 Biturbo, BMW M3, M5, Porsche GT2, Ferrari Enzo, Bugatti Veyron, Koenigsegg etc. = they should know why. I say all this and at the same time know that the Jaguar E Type V12 engine is an older design and runs at max. 6500 revs, less than M3 etc., but I just want to know if synthetic oil can really damage the engine seals and gaskets of our older engines.

Regards

Carlos

Hello Carlos,
I was once informed that using synthethic oil in old engines could cause bore glazing. And on that basis I would use a mineral oil. It would appear that synthetic oil can add to this problem
Have a look at this website: http://coxengineering.co.uk/bore.aspx

While it is aimed at diesel engines in boats some comparisons can be made. I am sure if you email or contact him through his web site you will get a reply.

regards
Sean