Just driven 1500km from France to Costa del Sol in Spain. We Averaged 100km per hour. With consumption of 6.4L per 100km.

 

I've had my 2005 SuperV8 for about 2 weeks now, with about 75% highway miles, I'm averaging 24.5 mpg via the computer. I expect this to drop to around 22-23 like my xk8, when I incorporate more of the city driving into the mix. I'm really impressed so far with the fuel economy...when driving civil, that is.

 

Doh! This was a typo. I meant to say ave=24.8. Today however, I reached 25.1 mpg ave.

 

What I read hee seems unbelievable to me.
I am driving 2004 Jaguar XJ6. Got it about 3 weeks ago.
During city driving (I go to work with this car) I get around 6.3-6.5 kilometres per litre. That would be 17.8-18 MPG (UK), 14.8-15.8 MPG (US), 15.3-15.8 l/100km.

During highway driving at 70 mph, I am getting 12-12.3 kms per litre. That would be 33.9-34.7 MPG (UK), 28-28.9 MPG (US), 8.1-8.3 l/100km

Average for last 9000 kms (I drove just 2000 from it) is 7.8 km/l, that translates to 22 MPG (UK), 18 MPG (US), 12.8 l/100km

 

2006 XJR:
As an aggressive driver I travel on highways at 80-90Mph with the occasional 130Mph every now and then.
In winter I get an average of 15.5-16.5Mpg around town, in summer 17-18mpg. On highways 20-22Mpg.

I only use Shell V-Power.

 

When I want to calculate real fuel mileage I never include city driving because conditions change every hour, and I never base my figures on what the computer displays, but by using the old fashion method of counting the liters I put inside the tank divided by the Km I made. To make figures as real as possible, I drive the same route several times and refuel at the same gas station (and at the same gas dispenser if available)
My driving style is pretty relaxed, which does not mean slow, I keep the tires at the right pressure, and I always use 95 octane fuel from a reputable brand (my own experience taught me to keep away from cheap supermarket fuel brands)
My fuel mileage figures show 28 mpg US, or 8.5 liters/100 Km. I think it is pretty impressive given the huge size of the engine and that of the car itself. My brother drives a diésel BMW X3 2.0 with a driving style similar than mine, and his mileage is just one liter less than the Jaguar. We all know about the light aluminum structure, but a superb engine and a perfectly balanced gearbox also play a key role in fuel mileage, so I must congratulate Jaguar engineers for a work well done.

 

2008 XJR: 16.4 MPG averaged over 17 fill-ups. Calculated using Fuelly App. I am lead footed.

 

Over the last 5627 miles, I've averaged 18.5 mpg (US). I do a lot of around the town driving so don't expect to get good mileage. I got a high of 24.5 mpg (US) on a 400 mile trip to East Hampton and back. The trip computer said I averaged 28 mpg.

I've also have been using Fuelly.com to track since I got it in July 2016. So far I've filled up 22 times. I've even been able to add it to my signature (see below)

 

Absolutely ! The computer on mine routinely claims 2.5 to 3.5 mpg better than the 'Litres-filled-divided-by-distance' method

 

Similar 2006 Super V8 with 137K miles and no cover underneath.
24 MPG US gallons in rural 2 lane driving
26 MPG US gallons on the interstate at 70-75 MPH
I try not to do much city driving so not sure about that

Best highway mileage was 27 MPG US on a 260 mile trip when the front shocks bottomed out due to a broken wire at the level sensor. Harsh ride but lo-rider stance may be slightly more aero.

I just searched the X350 manual looking for transmission level check (learned there's no dipstick) and read that engaging cruise control initiates a different shifting map - interesting. The manual says, "This map has been developed to reduce busy gearshift during cruise mode. It has also been developed to increase fuel economy."

 

2.7 TDVi.
Owned the car for approx. 4 months now and since then it has returned as an average a touch under 29mpg (Imperial)
Tank by tank average seems to be roughly 28mpg as my commute is approx. 60/40 motorway / 'A' roads with a bit of 'fetching the kids from school' mileage as well.
On a constant speed motorway run early morning - 70mph - it will return 40mpg easily... or so the computer says!

 

Everyone,

I get 22 to 24 MPG US in the city.
28 MPG to 30 MPG US highway driving at 65 to 70 MPH.

I do know check you final drive ratio. Jag has 4 different final drive ratios. I have a friend same car different​ has a higher ratio and he gets 34 MPG US on the highway.

 

In town about 18 mpg because DC area traffic is horrible. On the highway I've seen as high as 35 mpg at 60 mph. However, I typically cruise at about 70 mph or so. At that speed, I normally get about 32 or so mph.

 

At 80,000 miles ,10-30 synthetic oil, just changed out trans fluid with mercon sp and running shell v power, not to mention my consitant rich burn bank 2 & E.G.R. flow problem that I've been pulling my hair out for the last 7 months, I just completed a 1,080 mile trip and my dash told me I got 31.6 mpg average. I am amazed with this car, but for the life of me cannot figure out why I have these codes, I've had them now since I bought the car a little less than a year ago. I have a scanner (still trying to learn how to use the darn thing) so I erased codes before the trip, shortly after first fill up they came back on so I erased them again etc.,now get this when I reached my destination I read my mpg and noticed my codes changed to reading both banks burning rich & no EGR code so if I'm burning rich and ever get this thing straightened out I guess I'll get about 50 mpg. If anyone has any solutions please let me know!

 

Low 30's on the highway seems about average, if you keep your foot away from the accelerator pedal, and the cruse set.

 

Wingrider; thanks I'm still amazed at that milage especially with my codes, do you have any idea what may be causing them?

 

What are the codes???

 

The codes from day one I bought the car are P0175 & P0400, at the end of my trip the P0400 was gone and now for the first time I have P0172 what do you think?

 

A code P0175 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled There could be a vacuum leak. There could be a fuel pressure or delivery problem

Read more at: https://www.obd-codes.com/p0175
Copyright OBD-Codes.com

 

A code P0172 may mean that one or more of the following has happened: The MAF (Mass Air Flow) Sensor is dirty or faulty. Note: The use of "oiled" air filters can cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry. There could be a vacuum leak. There could be a fuel pressure or delivery problem

Read more at: https://www.obd-codes.com/p0172
Copyright OBD-Codes.com