There's a fellow that lurks here and on the Jag Forum who says he
is/was an engineer with Jaguar.  He states that the cars don't need
premium, regardless of what the factory recommends in the literature
and placards.  That said, given the fact that on the Internet everyone
is an expert at anything they want to be, I'll keep feeding my 96 VDP
premium fuel.

Mick Jagger

See, anything or anyone you want to be.

I recommend that you use what Jaguar states you should use.  This is not a
matter of falling in line un-necessarily, but a matter of value. I look at
it this way:  10 or 20 cents a gallon is a VERY inexpensive insurance policy
that my Jags will still be running and hold their value years to come.  With
the Nikasil fiasco from high content sulpher in Jags, BMWs and Mercedes and
warranty questions down the road -- who needs to take the chance?  Besides,
if using premium has kept my 1967 Jaguar on the road all these years with no
engine problems -- there must be something to it!!

If you decide to use a lower grade petrol than listen carefully for
"pinging" sounds when you accelerate. These sounds mean improper detonation
of the fuel and you should move back up to grade as soon as you can.
Continued pinging will eventually create engine problems.

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