Is this real economy?

ElRazur · 17 Feb 2006 at 16:24

Sincei returnedthe courtesy car (avensis t3 diesel). i feel like my fto is drinking more than usual.

To sort this out once and for all i did the following. I put in £15 of petrol at 86.9/litre and ive managed to get iirc 47.2 miles so far with some petrol still left in the fto. I should mention im doing urban driving only.

Going by the above describtion and values, am i getting any economy at all from a 2.0litre v6 engine?

Scottland · 17 Feb 2006 at 16:28

I work that out to be about 12MPG?! Whats the book MPG one these? I would have thought it would be nearer 20MPG at least...

iv-tecman · 17 Feb 2006 at 16:29

Well, say you've used £10 already, done 45 miles @ 86.6p. This works out to around 18 MPG.

We need better figures. you are better off setting trip to 0, filling from empty, and keep a record of mileage. Then work it out from this.

How much of the 16 quid is left?

Nozzer · 17 Feb 2006 at 16:33

You don't need to fill from empty. Just zero the trip and make a note of how much fuel you can get in the tank. Next time you fill up, note mileage, brim the tank again and note how much fuel fits in.

ElRazur · 17 Feb 2006 at 16:35

Nozzer said:
You don't need to fill from empty. Just zero the trip and make a note of how much fuel you can get in the tank. Next time you fill up, note mileage, brim the tank again and note how much fuel fits in.

that's what i did. i zerod the trip. and now it has a display of 47.2 but with some petrol still left.

Nozzer · 17 Feb 2006 at 16:36

ElRazur said:
that's what i did. i zerod the trip. and now it has a display of 47.2 but with some petrol still left.

You can't really work out consumption from the fuel guage. The best way to do it is to take a note each time you fill up, of how much fuel you can get into the tank, along with how many miles you've done in between visits to the fuel shop.

geiger · 17 Feb 2006 at 17:37

Either you run it to empty or fill it to the top. I used to run it on fumes all the time with a canister in the back and my mpg was quite consistent that way. Most people would say this harms the car in some way (I dont) so the filling to the top bit might be best (1 litre is 1 kilo so in a very tiny way, it'll make your car slower with a full tank).

Taking an average like Nozzer's says also works.

Vertigo · 17 Feb 2006 at 18:13

geiger said:
Most people would say this harms the car in some way (I dont)

Actually running out of fuel will cause no end of problems with a modern diesel.

Lashout_UK · 17 Feb 2006 at 18:26

And running a tank dry on a petrol car usually causes you to hoover all kinds of crud off the bottom of the tank - it's not in any way good...

geiger · 17 Feb 2006 at 18:31

For diesel I believe you but it never caused me any problem on petrol and I was doing that for years. Normally it would reduce the rev range before ever stalling, pretty precise

ajgoodfellow · 17 Feb 2006 at 18:54

I've heard that it's a bad idea for modern petrol cars too as the whole system needs to be re-pressurised

atpbx · 17 Feb 2006 at 19:21

Filling the tank is the best way.
Fill the tank, do 100 miles.
Fill the tank.
Record how much fuel goes in. IE 20 litres.
Divide by 4.55.
20 litres/4.55 = 4.39 (4.4 for argument)
100/4.4 = 22.7

ShakenNstirred · 17 Feb 2006 at 19:34

ajgoodfellow said:
I've heard that it's a bad idea for modern petrol cars too as the whole system needs to be re-pressurised

petrols do that on there own, when you turn the key they re-pressurise,
well my last 2 petrol cars did
on the diesel you will need to bleed the system if you run dry or when you change the fuel filter(my rover 600 has a bleed screw on the fuel filter)