Disappointing fuel economy plus fuel tank size

cyclonebri1

Forget tank capacity, it really does not matter.

Brim the thing.

Do your stuff and brim it again.

You have the mileage you have covered compared to the fuel put in?

Too simple?, no.

Inactive

cyclonebri1 wrote: »

Brim the thing.

Do your stuff and brim it again.

You have the mileage you have covered compared to the fuel put in?

Too simple?, no.

Far too simple..

skiddlydiddly

pgilc1 wrote: »

I think you're doing very well to get 36mpg out of a 2.0 petrol car.

I could get 45-50mpg from my old Clio 172(2litre) on A roads doing 50 ish mph.Just driving it to work I was getting about 37mpg.

There could be something amiss with the OPs car, although its not necessarily anything serious.

[Deleted User]

my 1993 2.0 vauxhall carlton will do 100 miles on 10 quids worth of fuel on motorway trips and will do 75 miles on 10 quid just doing small runs.


i was happy before, but i'm really happy after reading your figures.

and please no jokes about us women drivers:p

looby-loo_2

If you were going to the airport did you have heavy suitcases in the boot and a full load of passengers? That can make a difference.

thor

blued wrote: »

You need to brim the tank then do your trip (recording the miles with the trip counter in the car) and then brim the tank again. Then you work out from the amount of litres and miles what your MPG is. If you are guessing by half a tank you may as well have plucked 36mpg from thin air!

The only guess I am using is the quarter tank I had before I filled the rest of it. Of course this will introduce a margin of error but the needle was on the quarter mark so how far can I be out with this estimate?

thor

looby-loo wrote: »

If you were going to the airport did you have heavy suitcases in the boot and a full load of passengers? That can make a difference.

We were going to pick someone up so did not have any luggage to take down. and he came back in my bro's car along with his stuff.
The only passengers I had were 2 girls who together with me weighed less than 25 stones combined.

thor

cyclonebri1 wrote: »

Forget tank capacity, it really does not matter.

Brim the thing.

Do your stuff and brim it again.

You have the mileage you have covered compared to the fuel put in?

Too simple?, no.

Are you implying that the manufacturer's data for the tank is wrong? I suppose it would explain why 8 gallons appeared to have filled 3/4 of a reputedly 14 gallon tank.
My problem is that I rarely use the car and only put in a few gallons at a time(as much as I can afford) and will only get the opportunity to completely fill it the next time I have a big trip(not in the foreseeable future).
It is a bit disturbing to think Mazda could mislead so brazenly.

Kilty_2

thor wrote: »

Are you implying that the manufacturer's data for the tank is wrong?.

No, he's implying that the only way to accurately measure the MPG is to brim the tank, drive for a reasonable amount of time (not necessarily until empty) then brim it again and calculate MPG from the fuel you've used vs miles driven.

Tank size does not matter, fuel used is fuel used.

cyclonebri1

Exactly as above, plus you are forgeting that the tank will have around 2 gallons of fuel still in the tank when it reads empty, or when the warning light comes on so effectively you have 1/4tank + approx 2 gallons which is why your figuring is wrong.