Leaded fuel

Disused Categories Modern
1

Jag Folk,

Sorry if this has been discussed before, but I wonder about leaded/unleaded
fuel in the 3.6 lump in an '88 Sovereign.

In Europe it seems that in a couple of years time leaded fuel may no longer
be available. Does anyone know whether this engine can cope with unleaded
fuel, and if it cannot, what additives etc. must be added to keep the
engine running.

Also, what is the effect of ‘Sans Plomb’. Is it valve seat wear, or valve
guides, or bores? I’ve read all sorts of stories about the evil effects of
unleaded fuel, but many are contradictory, ranging from ‘it doesn’t matter’
to ‘don’t even use a tankful’.

Any chemists/engine designers on the list can give the facts?

Thanks,

Chris Dupres
Surrey, UK.
'88 Sovereign.

2

Steady Chris! Lets not start those ‘lump’ wars all over again…

Sorry if this has been discussed before, but I wonder about
leaded/unleaded>fuel in the 3.6 lump in an '88 Sovereign.

3

Well, if it’s a 3.6 engine in an '88 XJ40 I suspect it is NOT a lump,
but is instead the very nice and very dependable AJ6 engine.

My understanding is that Jaguar has been putting hardened valve seats
in their engines for a LONG time, going back possibly to the 1960s.
As such, there will be no problem running leaded fuel in any XJ6, be it
a SI, SII, SIII, XJ-40, or X-300.

If you suspected the question had been asked before, why did you not
check the archives before posting it?–
–Pete Crosby (pac@atl.hp.com)

              1988 BRG XJ40
              1988 Mazda 626 Turbo
              1995 Ford Windstar kid-hauler
              (Now, what other companies does Ford have a piece of?)

Sorry if this has been discussed before, but I wonder about leaded/unleaded
fuel in the 3.6 lump in an '88 Sovereign.

In Europe it seems that in a couple of years time leaded fuel may no longer
be available. Does anyone know whether this engine can cope with unleaded
fuel, and if it cannot, what additives etc. must be added to keep the
engine running.

Also, what is the effect of ‘Sans Plomb’. Is it valve seat wear, or valve
guides, or bores? I’ve read all sorts of stories about the evil effects of
unleaded fuel, but many are contradictory, ranging from ‘it doesn’t matter’
to ‘don’t even use a tankful’.

Any chemists/engine designers on the list can give the facts?

Thanks,

Chris Dupres
Surrey, UK.
'88 Sovereign.