I never saw more than 19mpg around town with mine.:o

I've said this in the past, and I stand by it.
My old gold 2.5 gave me around 32 mpg local, but on a run around 42mpg, both on petrol. (I checked mileages against known calibrated police equipment to compare my speedo). Running on lpg I got similar results, on lpg always checked with a full tank.
When I swapped to the blue one, I transferred the lpg over. Once I'd sorted the car, I got similar results. Now I've changed to the silver on, about 9 months later (having checked everything through) I'm back to those levels. Good on petrol, but remember I'm normally on 55.7p/l lpg!

Stewart

42mpg is almost 15km/liter.
Well it might be possible, but it would be driving with an egg under you shoe.
My 1.8 MG F will give me that type of economy on a long run, none of my Rovers ever have! Not even close.
It would be nice to know how you have measured this.
32 mpg = 11.33 km/liter for running around town. Also significantly different from anything I have ever been able to obtain.
Pipe and slippers come to mind?;)

The best I have managed is 32mpg on a long run keeping to 3K revs or less and brim to brim measurement.

I am adamant it can't be done, and i am prepared to put money on it.
So if anybody is prepared to take a bet, I'm open to any challenge.!
I notice the car in question is an automatic, so I am convinced there is skulduggery involved!:getmecoat:

No skullduggery involved, & shame I'm not a betting man as you would lose!
Attention to detail with the servicing and careful driving (more in a moment) are the keys.
Obviously, engine servicing, but I have serviced everything since I got the car (and the same with the previous two). Iridium plugs; I am on gas, Things like the idle valve have been scrupulously stripped & cleaned; a slightly fast idle can waste a lot of fuel. But don't forget the rest of the car. A rolling resistance on a brake; all mine have bee stripped, cleaned and greased where necessary. The handbrake too has been done and a modified compensator fitted. Also I don't carry loads of extra weight in the boot - except for the lpg tank! To compensate for that, my tyre pressures are now 28F/30R, after much experimentation over the years.
As for driving, when I was a youngster I fitted a vacuum gauge to my A30. That taught me a lot about economical driving methods, pity they aren't still available. I used to get 48mpg out of that car. I'm not going to list all my driving habits, I think the word "anticipation" sums it up. Think ahead, so you drive smoothly with no excessive braking. As ex-police (civilian side) I learnt to respect speed limits too. Time & time again, keeping rigidly to the limit (though possibly exceeding it on dual carriageways by a small margin) I have managed to keep up with those that ignore them. I don't hang around and cause queues though! How many times do you pull up at the pump and leave the engine running while the 3 cars in front fill up? More waste......etc etc....

Stewart

I have 2 V6's. I use the 'FillUp' app and record the mileage and fuel quantity at every stop.

In the 4 years I've had one car I've averaged 23.96mpg (over 31,628 miles)with a maximum of 28.29mpg.

The other I've had for 2 years and it has shown an average of 23.66mpg (over 5,894miles) with a maximum of 28.05mpg.

I've deliberately avoided declaring the specification of the 2 cars as it hasn't really been considered relevant yet in this thread.

I think you are doing something wrong in your calculations!
And you say you drive on gas. How do you equate that to mpg? that we can compare to petrol?
The calorific value of gas is lower than petrol.!
I think you are using a conversion factor, and multiplying instead of dividing, or the other way around, depending on you maths.
Show us your calculations, please. This is getting better than an Agathe Christie.

This is too good to be true!;)

Stewart, please could you reveal whether you are measuring the petrol consumed by the brim-to-brim method?

Simon

Crikey, I have never got anything near 42 MPG out of my white gold 2.5L auto tourer! With relatively gentle driving, it averages 9.1 L /100 km (~31 MPG) on long runs. My top motorway speed on those runs will be around 75 MPH. I daresay that turning off the climate control and keeping the speed no higher than 70 MPH might see that rise to 32-33 MPG; but 42 MPG? Never! Car is serviced regularly with working VIZ motors.