Actually, "Regular" fuel in the majority of the US is 87 AKI octane, using (R+M)/2 method. In higher elevations, Regular grade is 85 AKI.

 

True, sorry - I'd got in in my head that 95 RON was the minimum, but 91 is the minimum and 95-98 is recommended. So it probably isn't a knock issue.

Car still bunnyhops occasionally under hard acceleration from rest, but it's not a big deal.

 

Sorry, meant to type 87AKIfor regular. Never seen 85AKI except hi altitude elevations as you mentioned

 

A waste we get looped into here. 99% of the gas stations have 87, 89, and 93. Some of the 7-11s have 91 but I don't buy gas at 7-11. So my premium gas cars that require 91 get 93....

 

Weird, I've always seen 87,90,93 pretty much everywhere except Maverik stations where they have 87, 89, 91, 93. Of course at over 4000 foot elevation, take two points off every grade. (what a rip, we pay for the name, not the octane)



Then again, I haven't bought petrol in Texas for many years.

 

High test in SoCal is 91. There is at least one Union 76 with "racing fuel". i believe it is 99.

 

All of this discussion, as interesting as it might be, is pointless as the OP has not been back since Nov.1 last year.Another drive by poster.

 

But we were able to share and learn about each other's gas issues

 

It is interesting to talk about this stuff - if the OP misses out, more fool them...

 

Just acquired my very first XKR and i am having the exact same issue. Wondering if anyone actually solved this or if it is worth starting a new thread.

The car is going into a Jag specialist in Glasgow in 2 weeks time but its pretty disappointing at the moment to have this amazing car that otherwise drives perfectly except for this one annoying glitch.