Went on a 220 Mile road Trip to the nearest race track and so amazed to be able to get 27 MPG averaging 70 mph!
The car is 2018 F-Type R with 21k miles , is modded with AlphaJag ; lower, upper pulley, ECU and TCU, wider front and rear tires , car is making around 700 HP

 

Just remember, it's making tens of HP when cruising at 70mph.

 

How much 'oversized' are the tires, as that screws with the calculations. Cruising MPG can often be quite good on most cars, my C6 will be in the 30s if you drive it gently on the highway. Even my old V12 benz could near 20mpg at high speed cruise, but was sub-10 around town. Always balances out.

 

I should have said wider otherwise they match stock diameter. Verified mpg at the pump, it pretty accurate
You got to remember tuning aspect also releases torque at the lower RPM which actually helps MPG

 

CarlB,, Totaly yes , although V6 Ford mustang with less half the horsepower 300hp
I could only get 23mpg best hwy and if I'm not mistaken V6 f-types don't do as good of mpg on hwy either. This is a modified car with way more power than stock yet it's getting around same mpg as stock or better

 

Yeah you'll see this on big displacement torque engines with high gearing. Going down the road at 70 the engine isn't turning under 2000 rpm is yours awd or rwd?

 

My 2017 AWD R gets the best mileage of all the cars we own. On an easy stretch of interstate, it will average a bit over 31MPG. Over longer periods it will sit somewhere in the 28-29MPG range most of the time. Unless I get a heavy foot, of course. It's not tuned (yet), but I don't expect that to change the numbers much for easy highway driving. Lead foot driving -- that's a different story. Even speed doesn't kill the mileage too bad. My last road race, I averaged 110MPH, over 118 miles and averaged just under 26MPG. Not a lot of drastic speed changes, like you would see on a track through. Acceleration, especially rapid acceleration, sucks down the fuel.

 

Yep mine is tuned with both pulleys, and I still can be usually around 28-29 with cruise control on interstate driving around 75. Mine is also RWD. On the other hand, local "fun" driving in manual shift, I feel I can actually see the fuel gauge move in real time

 

You must still be smoking cars at the track. Then they want your secret. Keep it going alex

 

Our stock 340HP base model gets 32 MPG on the highway. Eat your heart out.

I remember some groups bragging how LITTLE their MPG was when flogged.... Now, That's is amazing. (14MPG was for wimps, LOL)

 

Assuming there is an actual time slip from this 10.77 run and not just from Dragy?

 

35.2 UK mpg.
That's the fuel consumption according to the trip computer on my Jaguar F-Type V6 manual 3 litre after driving home 198 miles from Doncaster to south east Essex averaging 65 to 70mph, on a 18.5 mile town trip she achieved 28.5 mpg with a cold start engine. . however, i didn't buy an F-Type for fuel economy.

 

Running steady freeway speed I get really good mileage. As soon as hit surface streets it plummets. I'm not sure about indicated, but actual is over 27 at a steady 80mph, but well under 20 in town. The lifetime average remains at 18.5 with full tank averages at high of 25.1 and low of 12.6.

I did not buy mine for fuel economy either. The 6MT gets worse mileage than the 8AT.

 

I verify my MPG every tank of gasoline. The indicated MPG is consistently 1.5 to 2.0 MPG more than the actual calculated MPG.

When our automatic F is in the Manual mode, I manage to increase fuel consumption, too.

 

My gas mileage is absolutely horrible due to my typically doing shorter stop and go runs not at highway speeds, and I love it ;-o

 

I set my display to show the instantaneous consumption - lowest I've manage so far is 3 mpg, highest 99 on a trailing throttle (presumably fuel cutoff).

 

That matches what I've seen, but I set my display to show none of that. I do record and clear it all each time I fill up: trip meter, average speed, fuel economy. I lost my chart at some point when I was fiddling with the spreadsheet, but there's a correlation between higher average speed and higher fuel economy. The spreadsheet also calculates average daily mileage, but that's become less useful now that I don't commute.

 

You're violating not only the speed limit but also the laws of physics.

 

Have you had a chance to dyno it by chance? Certainly very good times that may affirm your 700HP estimate, but objective data rules! I, too have pulleys and tune (VelocityAP) on the engine. I'm led to believe the stock motor is 10 psi boost, the lower pulley adds 3 1/2 more, then the upper pully another 1 1/2 for a total of 15psi. I'm very pleased. My last time at the PBIR road course I gained about 6 mph on the back stretch (~142 mph - 148 mph) which infers quite bit of additional HP.

I've not dyno'd it since the supercharger pulley, but most folks claim upwards of 640HP(engine) and 600 ft. lbs. Some claim 650 but I've not seen dyno tests to validate.

Hope the others at the track were dropping their jaws!

 

I canna change the laws of physics, but gladly violate them. Speed limits? Pffft. In town and in neighborhoods, definitely. On the open road, they're just a suggestion.

For speed versus economy, it's complicated. Stopped, it's zero MPG. Moving, it's a matter of getting into a gear where power lost to drag can be most efficiently generated. The old Saab factory service manuals include charts for power, torque, and specific fuel consumption, which is a bit of a mirror image to the torque curve.

Now I'll have to see what I get idling in various gears, just because I'm a nerd.