Is this Fuel Consumption right?

27th August 2010, 09:01

Hi,

a little bit confused here guys.

I have a 97 VTR,

i filled the tank yesterday (£50!! ffs) as i was going to work out my MPG as per the sticky, and drive "economically" as i can as per the sticky threads instructions.

i have so far done 17 miles and used 1/4 of the tank!

i havent drove like a dick once. i havent over rev'd it. i havent done anything.

i travelled one junction on the motorway to avoid some traffic yesterday, but didnt kill it.

and other than that its just been driving round the local area.

The only mods i got are an induction and a backbox.

changed oil last month, and had new Sparks the month before that.

i was thinking maybe my fuel gauge is reading incorrectly?

i am going to take it to the petrol station and try filling up again. see how much i can fit in.#

is this kind of fuel consumption normal when driving economically? lol

if so... i am out!

27th August 2010, 09:09

happened to me once. Thank you sainsburys for selling me hot petrol. It shrinks when cooling down and I spend over £1 per litre of air.

27th August 2010, 09:11

what!?

thats what you reck it is?

that kinda makes sense. i filled in til it clicked 5 times, and left some time inbetween each click. but when i drove off the forecourt and down the road went to work, less than 1 mile away, then at dinner the gauge had already moved!

27th August 2010, 09:14

fuel leak?

27th August 2010, 09:16

depends if you parking on a hill... but fill it up, and you will see how much to fill it, that will show you accurately how much youve used for 17 miles...

27th August 2010, 09:22

Quote:

Originally Posted by liam-o

fill it up, and you will see how much to fill it, that will show you accurately how much youve used for 17 miles...

yer thats my plan. i am going at 12, so will know then.

i cant see it being a fuel leak, but it could be. i have noticed that it does seem to use alot of fuel. last time i filled it up to the top i only got 180 miles out of it.

i had a westie b4 this, and that used to do about 400...

there must be something wrong here.

i dont park on a hill either. my street is flat.

27th August 2010, 09:44

180 miles to a full tank in a VTR

You have something wrong there mate.

You are using all your gears yea lol.

I ued to get over 300 miles out of my VTS with de-cat etc and that was with 'spirited' driving lol.

Check your fuel lines out mate

27th August 2010, 10:10

Yer, theres gotta be something up.

i notice though that if i put in a tenner at a time it seems to be ok on fuel, but if i fill it it just drinks it.

sound plausible?

maybe the fuel tank is cracked half way up maybe?

27th August 2010, 12:52

nah, just filled it, and it took 4 litres. so it looks all is well.

and my gauge hasnt moved!

looks like something stuck...

crisis averted!

27th August 2010, 12:56

If you leave it on your drive after you've filled it up. Light a zippo and slide it under the car. If your car goes up then you can diagnose a leak.
fool proof!

27th August 2010, 13:01

i got 1/4 of a thank from only doing 25 miles in my vtr Not good

27th August 2010, 13:04

Quote:

Originally Posted by adamskiTNR

If you leave it on your drive after you've filled it up. Light a zippo and slide it under the car. If your car goes up then you can diagnose a leak.
fool proof!

OK, COOL. SOUNDS OBVIOUS. I WILL GO AND DO THAT NOW.

LOL

27th August 2010, 13:19

doing low mileage and then filling back up always biases the results. This is because there is actually a lot of margin for additional fuel being put into the tank during a fill up. If you only fill it up to the first click then there is room for at least another 2 litres. If you cover 20 miles and use 2 litres and then decide to fill up, you could end up putting anything between 2 to 4 litres of fuel. Which will skew the results...

20 miles / 2 litres = 10 miles per litre or 45.5 mpg
whereas
20 miles / 4 litres = 5 miles per litre or 27.8 mpg

Which is quite a difference.

This difference is minimised, and you get a truer reflection of your actual mpg by using as much fuel as possible before filling up.

For instance

This time you cover 400 miles using 40 litres (remembering you have a variation of 2 litres when you fill up so)

So
400 miles / 40 litres = 10 miles per litre or 45.5 mpg
400 miles / 42 litres = 9.5 miles per litre or 43.4 mpg

Which gives a more accurate indication of your TRUE mpg.

So you're best to cover as much distance/use as much fuel as possible before refilling.

Don't trust the fuel gauge - the level will adjust according to the inclination of the vehicle - This is why it helps to return to the same garage for fill ups as the inclination of the vehicle is always roughly the same, so you can stick enough fuel in.

See how much distance you cover from half a fuel tank! Then report back!

Ads

27th August 2010, 13:45

Right! cheers Ads

i have refilled up again, and reset the clock...

i am going out on saturday (chester zoo!) so some combined driving there. will report back saturday night with my results.

nice 1 man.

your thread has made me think about MPG and actually try to make my engine work for me, not the other way round!

27th August 2010, 13:54

Quote:

Originally Posted by Newtz07

your thread has made me think about MPG and actually try to make my engine work for me, not the other way round!

LOL!

Have fun and if there's any probs then report back

27th August 2010, 14:11

I feel lucky get between 400 to 450 miles in my vts with raceland manifold decat and straight through to a magnex and induction kit as well

27th August 2010, 16:21

the only mods i got are induction and straight through magnex...

but all seems well. gonna run her out for a bit and report back to Ads!

cheers guys,

have a good weekend all

1st September 2010, 08:33

Right...

here it is.

i have covered 170 miles and i have just hit the halfway mark!

thats alot better than my usual MPG. i have been driving smoothly and changing at about 2500 rpm.

and thats all urban really. i did go to chester zoo on the motorway, and i did put my foot down at one point as we was running late to meet some people so there was a little bit of speeding done there. but i accelerated gradually and held my high speed. so that was the best i could do in that situation. i estimate i would of done nearly 190 miles by now if i had stayed at 56 mph in the slow lane. but fuck it.

will work out my MPG when i fill up!

cheers ads! i owe you a beer bro!

*EDIT* worked out MPG: 34.4!! better than my other usual driving!

1st September 2010, 13:02

Quote:

Originally Posted by Newtz07

Yer, theres gotta be something up.

i notice though that if i put in a tenner at a time it seems to be ok on fuel, but if i fill it it just drinks it.

sound plausible?

maybe the fuel tank is cracked half way up maybe?

To be fair my VTR does this, granted its an 02 but hey.
But driving 18miles and using a quarter tank isnt right lol.. I think i drove 65 miles and i used a quarter but then i was driving like a dick

6th October 2010, 23:40

I do 40 miles a day, 2 journeys(80 miles) the fuel gauge hardly drops(when its half filled up), but on the 3rd journey(40 miles) the fuel gauge drops considerably quicker and seems to drink fuel for fun.

Strange that it seems to hardly drink any fuel when its on the half way mark, yet it drinks it all up when it gets lower on the gauge. Its nothing to do with how i drive, is this normal?

7th October 2010, 00:08

Quote:

Originally Posted by ManGo-SaXo

I do 40 miles a day, 2 journeys(80 miles) the fuel gauge hardly drops(when its half filled up), but on the 3rd journey(40 miles) the fuel gauge drops considerably quicker and seems to drink fuel for fun.

Strange that it seems to hardly drink any fuel when its on the half way mark, yet it drinks it all up when it gets lower on the gauge. Its nothing to do with how i drive, is this normal?

Does that on mine, like at 250 miles on the halfway so im thinking "nice, 50mpg!!"
then suddenly it drops and gets to like 430 a tank and im like ohh..

7th October 2010, 01:03

i drove my vts from calne to rockingham french car show which is about 250miles thete and back, and i only put 30quid of super unleaded in it from pretty much empty and the petrol light didnt come on at all. i was quite pleade with that considering its got the full supersprint system with decat and a panel filter

7th October 2010, 10:26

Quote:

Originally Posted by piranhamatt

Does that on mine, like at 250 miles on the halfway so im thinking "nice, 50mpg!!"
then suddenly it drops and gets to like 430 a tank and im like ohh..

Mine does this...pisses me off tbh

always get my hopes up about the mpg, then it all goes tits