Sportbrake fuel consumption!

[CliveRothwell]

OK, we bought a lovely 2.2 200bhp Sportbrake last month. A stunning car, it has 18000 miles on it and is just 3 years old. We are the second owners. FJSH, bought as a Jaguar Approved car from Matford Jaguar in Exeter. Both tank fills are way off the mark.
1st tank achieved 370 miles using 46.59 litres giving 35.86mpg
2nd tank achieved 470 miles using 61.32 litres giving 34.5mpg

The car computer says the car had averaged 47.7mpg for that last tankful.

The Honest John website real average is 41mpg

Jaguar official figure is 52mpg

The X Type 2.2 D Estate that the XF replaced achieved a lifetime average over 3 years of 45.23mpg. Jaguar figures for that car is 49mpg so you can see that I'd be expecting something near 45mpg given that the official figures for the XF is supposedly better than the X Type.

What are other owners getting over a full tankful please?
Am I being unrealistic?

Cheers

Clive Rothwell

[J44EAG]

Most cars are incredibly over optimistic with their fuel averages. The modern Jags I`ve owned have always been at least 10% out. Try doing a GPS point to point run over a long straight road and see how the odometer compares to the GPS. I think you will find you clock up the miles on the car faster than the GPS indicates. Taken to its logical conclusion, a car which has covered 100k miles has in fact probably only covered 90k. That means the parts wear out quicker than ever!

Then there is the speedo. That is usually 10% optimistic as well! At 60mph, you are probably only doing 54mph. All this tends to make a monkey out of fuel consumption figures.

Mike.

[CliveRothwell]

Well, yes Mike, I agree with all that you say. I'll try the GPS point to point, it sounds like a good idea. Never the less, on the figures above, this car is at least 25% more thirsty than Jaguar figures.

[poprivet]

All manufacturers data on fuel consumption are performed under 'laboratory conditions' whatever that means, I suspect a pefectly flat smooth surface, hard tyres, mirrors folded in, aerial removed, running lean, engine already at optimum temperature, revs and load etc.etc.

They bear no relation to what will be achieved under real conditions. Exactly the same with emissions, just look at what VW were trying to get away with. When you read the small print there is always a get out. Once one gets away with it all the others have to follow suit as the customers usually compare published figures.

My neighbour has recently bought an expensive new diesel as the road tax was about to go up and 'they do lots of miles to the gallon'. He only usually goes to the shops a couple of times a week

[Zennan101]

Hi,

If it helps I have been monitoring my 3.0 XF over 15 months/10K miles.

Jaguar Urban Cycle claimed = 42mpg
Cumulative as recorded by Trip computer = 33.3mpg
Actual = 31.8mpg

That's 24% less than Jaguar claimed and the Trip is approx 5% over optimistic.

Rod

[CliveRothwell]

Thanks Rod - that's the sort of message I was hoping to get at some point . Anybody else got some real Sportbrake fuel consumption figures?

[franrca]

If it helps add to the conversation, I have a 2013 2.2 (200bp) Sportbrake and since December, I have an average of 38.9 mpg for 2,912 miles covered (trip computer registered).

[CliveRothwell]

Thanks - that's far better than we are getting. Any more owners with figures?

[CliveRothwell]

Just been to F1 Grand Prix in Austria and the car returned 45.03 mpg measured tank to tank. MUCH better! And that was at speeds of up to 130KPH

[3.8etypephil]

Unfortunately, the only fuel consumption figures which manufacturers are allowed to quote in advertisements and literature, are the EU official figures, which are obtained by unrealistic laboratory tests designed to favour small petrol engines, diesels in general, and most of all hybrids, hence the amazing, but completely unobtainable figures quoted, especially for the last group. Sadly, current reviews and "road tests" also seem to use the same data, rather than actual test figures which were used in the past.
It may surprise some to read that over the past 12,000 miles of mixed motoring, in Britain and mainland Europe fully exploiting the performance, our 2013 XFR has averaged more than 30 mpg measured brim to brim. Significantly better than the "official" figures would suggest is possible.

[Foffer]

My XF 2.2 200 Sportbrake shows 41 mpg average but actually (tankful to tankful calculation using the odometer) does 36 mpg. This is over a couple of month's motoring which comprises half short trips in town and half open road. Splitting this I notice according to the computer I get 25 mpg in town and 58 mpg on the open road so it seems this is not a good town car but good on a long run.

[J44EAG]

Not perhaps unexpected.

My 2004 XJR does little more than 18mpg around town but can nearly double that if soft pedaled at 56mph on the motorway. Pedal pumping around town in low gears can only but increase fuel consumption. It gets worse if on the daily milk run, the car doesn`t even get half warm by the time you return home!

Its very much horses for courses when it comes to selecting the right vehicle for the job. I`ll use the XJR for fast open road trips and our disabled, converted Peugeot Tepee diesel van, six speed auto for around town work where possible. Even then, it isn`t ideal. I`m always conscious that I`m clogging the DPF filter on short journeys. Sense says I should use the well tweaked XJR, but it is fitted with fast flowing sports cats which don`t operate too well when cold. That is an issue I fight at MOT time when I ask the tester to do the fast idle test for emissions as if the car has been standing at idle on the ramp, then the emissions go into the red! That is just my particular car which when cold becomes a bit of a smelly one! I`m amazed it is still legal but it is!!

Mike K