Full or Half Tank - what do you think?!

[Purvesh]

Let me put this to you guys...

Do you think you'd get better mpg and performance (slight weight factor of a full tank) if you fill up your car to half way and drive as opposed to filling it to the brim.

TBH I always fill it up about half way, say around 35litres and get about 225 miles. Do you think there'd be any significant difference in how the car felt and performed if I filled it up full all the time. Keep getting this perception the car would be less economical and sluggish.

Got my fire suit ready chaps :eek: :p

[clubsportmatt]

Out of habit I always fill it to the brim, then wait until the fuel light comes on to refill. This usually gives me in the region 280 miles. (with no motorway driving) Not much more than your getting though! :S I think having a full tank encourages me to drive with economy in mind......because as soon as i'm lower down in the tank it kinda goes out the window!! lol What kind of mpg are you getting post remap Purvesh?

[Purvesh]

What kind of mpg are you getting post remap Purvesh?

It's definately up about 2-3 mpg Matt, well worth getting it done :cool:

[330ciSport]

TBH I always fill it up about half way, say around 35litres and get about 225 miles.

If you really get 450 miles out of a full tank then that's some going. Do you ever come out of 6th?

I used to get 260 out of a full tank with my old 330 on a nornal run (i.e. not being economical).

[Chaos]

Blimey, I get 260 out of either of the M3s if I use them to commute (so regular driving and heavy traffic), I'd be worried if I only got that out of a 330. :confused:

Less weight is almost always more efficient, so your question is probably well-founded, but you're also probably dealing with fractions. Saving 10kg out of the ~2 tons you're driving? Not going to make an enormous amount of difference on it's own I'd have thought. Plus you've got to stop twice as often. ;)

[Mud]

Taking a big shit is probably gonna make more difference that just filling a tank up 50%

[Chaos]

I've shared rooms with him, he's serious when he compares his bowel movements to half of a 12-gallon tank, it's true... :(

[dodgyken]

Apparently the walls of the Golden Anker tell of Fas releasing 6 gallons of fluid when you and him shared a room :eek: :eek: :eek:

[Purvesh]

If you really get 450 miles out of a full tank then that's some going. Do you ever come out of 6th?

I used to get 260 out of a full tank with my old 330 on a nornal run (i.e. not being economical).

It's mainly motorway and a few B roads really.

Unfortunately my 6th gear is reverse :eek: :p

[330ciSport]

It's mainly motorway and a few B roads really.

Unfortunately my 6th gear is reverse :eek: :p

Then I tip my hat to you. You should get some sort of green tree hugging award for that.

[Nickleback]

Personnally I brim my tank (330 with e-maps re-map) with cheapest shell where ever I find it & average mpg on mixed driving is 29.6 to 30.3 ;)

[clubsportmatt]

I have had 420 miles out of a tank, all but 50 miles was motorway cruising. Think I would have been near 500 if it was all on the motorway.

[alexsh1]

Do you think you'd get better mpg and performance (slight weight factor of a full tank) if you fill up your car to half way and drive as opposed to filling it to the brim.


I think this is a question all F1 strategists bring up.
Its always been a question of what tyres/when fuelling (providing driving and engine is the same). Probably the intuitive answer to your question would be yes, you'd get better mpg though you have to do fuelling more often, but you do not care about the last as you are not timed, right? :D

Consumption... :(
In London I sometimes get 23mpg but in a normal heavy traffic its more likely to be 18-22 mpg
(or even 15mpg when I have a heavy foot)
As soon as I hit motorway it goes up to 33mpg
Its all on 2.5L engine.

[Durgesh]

I don't think it makes much difference. I also Fill to the Top, and then fill when the light comes on... less trips to the petrol Station.

As most know, the first of half of the tank used it always bigger than the second. ;-)

[mysticm3]

I havent actually thought about this question, good thinking!

say full tank weights 62kg (1ltr approx 1kg) then half tank is 30kg and to shed 32kg on a car is almost impossible in usual ways unless you strip out lots of stuff so I'd think theratically it should make slight difference to performance and handling.

Have a look on bmw owners book the figures BMW quote I think are with 1/4 tank?

[Chaos]

6 gallons of petrol weighs 16.4kg (750g/litre). I'd put £50 down right now that the average driver in the average decent car on an average road wouldn't have a freakin' cuckoo whether you'd put 16 kilos in or taken 16 kilos out of their car if you didn't tell them. Unsprung weight, maybe you'd feel it ever such a little in the corners, but 16kg of sprung weight - especially low CoG weight like fuel - is naff all on a ~2 ton car.

[dodgyken]

6 gallons of petrol weighs 16.4kg (750g/litre). I'd put £50 down right now that the average driver in the average decent car on an average road wouldn't have a freakin' cuckoo whether you'd put 16 kilos in or taken 16 kilos out of their car if you didn't tell them. Unsprung weight, maybe you'd feel it ever such a little in the corners, but 16kg of sprung weight - especially low CoG weight like fuel - is naff all on a ~2 ton car.

Speaking of 16 kilos - how is the diet going :eek: :eek:

TBH when it comes to weight and how it effects the drive, I would say I have only noticed:

1) Far more direct steering when I shifted to wheels that were 4kg per corner lighter

2) Shed about 100KG of weight from a car.

3) Gone from a Z4 to E46 M3 cab or an E39 M5 around the ring - boy can you feel the weight transfer in the corners.

4) Gone from the Alpina without fancy suspension to Alpina with fancy suspension - and the almost complete lack of body roll. Further heightened if you get a go in a Radical

[arkenphel]

is naff all on a ~2 ton car.

Dan, we don't all weigh as much as you do.:p

My car with me inside it probably weighs less than 1600kg...:D