fuel consumption

[CliveRothwell]

We brought the XJS down from mother's at the weekend. It returned an impressive 27.4mpg - it bodes well for the forthcoming half term trip to Holland.............

The best thing was that we wern't really trying! I'm sure somebody can better that though......

[davidr]

Clive - can't beat that! My Celebration is currenty averaging about 26mpg. Took it on a long trip through France last autumn and averaged just over 27 for 1500 miles.
The V12 is a different story! Currently shows an average of 17.4mpg on the computer!
David

[Brakebuster]

in the 220 miles i have done since reinstating my V12 XJS , i have averaged 28mph , and got 17.6 mpg

not bad to be honest, and better than expected ,

have reset the trip comp now, to see if it tallies again

BB

[oldtimer]

Clive,
Yes, pretty impressive
Back in the early 80's we drove down to Barcelona in our Series Two XJ12 on carbs, despite my best efforts I could not fiddle the fuel receipts to make 15 mph. My memories of it are, that it was very fast and smooth-- we still have the car.

[CliveRothwell]

Well there we have two great replies: there's not many folk who can say they have driven to Barcelona in a car, let alone a Jaguar! It's going to Holland next week so it will be interesting to see if it can be bettered. I'll see if I can get photographic evidence...............

Try as I might though, i can't get it to give any tell tale signs of burning oil either on the over-run or on initial start up.

Cheers

Clive

[PaulGover]

Well there we have two great replies: there's not many folk who can say they have driven to Barcelona in a car, let alone a Jaguar!
...

How about Lisbon via Bordeaux? That was in my old XJ6 (primitive fuel injected 4.2) in about 2001, and got about 19 mpg as far as I remember.

I've seen over 22 mpg from my 5.3 XJS V12, but that needs warming the engine up, then resetting the trip computer, and finally driving about 100 miles up the A34/M40 on a good day! Normally it does around 19 on a decent run.

[CliveRothwell]

That IS a long trip!

I like the honesty in your reply Paul, I like the idea of getting the engine hot and THEN re-setting the computer is a great cheat! Now if you free wheeled as well, there's no saying what your car might achieve!

[PaulGover]

Indeed, I believe that white Mk 2 that appeared so many times on TV achieved over 99 mpg as it dived into the gravel pit

[ng4xjs]

If it helps. I drove up to Yorkshire (to see my parents) last weekend from Kent via the A1 and averaged about 28mpg over some 600mls (two up with luggage). I only really keep a visual on what's going on just to make sure things are running properly. Last year I was significantly low and it turned out to be a bad air flow meter.

Happy days
Nick

[CliveRothwell]

Well, we returned from The Netherlands today. The car achieved a remarkable 30.2mpg on a good long run from Apeldoorn to Gouda - 2 up, air con on, dead flat smooth roads, 65mph max.

Very pleasing for a 4.0 litre XJS. So, can your XJS do better?

[davidr]

Clive - not bad!,
I've been up to the Shelsley Walsh hill climb today in my Celebration convertible - a round trip of about 200 miles. Mostly A roads and motorway with the top up but also some top-down country roads. Average was 26.9mpg which I was quite pleased with until I read your post!
I shall have to try harder!
Regards
David

[CliveRothwell]

I'd be delighted with your figure in the UK David. That is a more realistic test. Take your car to Holland and try it for yourself, you might beat our figure quite easily!

[Jag190902]

Took my 3.6 xjs to Gleneagles last year and we managed 32mpg each way - all motorway though!

[CliveRothwell]

Good result! You need photo evidence though.......................!

[ptjs1]

Clive,

We all know that photo evidence of the trip computer isn't appropriate! Impressive one-off trip trip computer figures are quite easy to emulate!

The only way to accurately assess fuel consumption is to do brim-to-brim tank calculations and also to do that over a number of tanks to avoid filling discrepancies.

I keep very detailed figures on all my cars and the XJS trip computer is really quite accurate compared to other models. Over the last 10 years, my calculations show that my trip computer is about 3% optimistic compared to real consumption.

Paul