I am looking to buy an early GERMAN 1981 JAGUARE XJ-S V12 (pre-August 1981). QUESTION: Does this EARLY V12 have HARDENED VALVE SEATS so I can use UNLEADED as the V12 is NOT an HE ? Thanks; Ed

 

Yes, Ok to use unleaded.

Cheers
DD

 

Doug thank you for your reply regarding early 1981 XJ-S V12 using unleaded fuel.
Does that mean that the early 1981 V12 engines had hardened valve seats ?

All the best; Ed

Yes, Ok to use unleaded.

Cheers
DD[/quote]

 

Yes, hardened valve seats. Actually I've heard that all Jag engines have hardened valve seat, period. Don't know if that's true.

But, anyhow, I went to an early 80s Jaguar parts catalog that I have, which covers pre-HE V12s, and all variants, including USA/export variants, use the same valve seat. Since USA has had an unleaded fuel requirement since '74/'75.....


Cheers
DD

 

Correct, all V12s can use unleaded. European pre-HE must have 98, although I have used 95 when nothing else was available but then it is important to use a light foot and not with a heavily laden car. Top up with 98 asap, run down and then brim with 98 again.

 

Thanks Per for your help regarding 1981 pre-HE XJ-S V12 using Unleaded.
All the best; Ed

 

Thanks Doug for all your great help with my 1981 pre-HE XJS V12 using unleaded.
All the best; Ed

 

Just as well. Leaded has not been available at the pumps in Europe for around 10 years or more.

Anyhow, I always thought that ANY vehicle equipped with Cats, must be run on unleaded.

Or does this vehicle year not have Cats?

 

Hi Translator. No this 1981 (Pre-HE) XJ-S V12 does not have catalytic converters as it was first sold in GERMANY in 1981.
ALL THE BEST; Ed

 

With V12 engine, it's better to use unleaded 98 if the car is a non catalyst one.

 

If you are really worried there are products you can buy which condition the fuel with additives which replicate what lead used to do. Fuelstar is one of them, I have two on my '74 XJ12