Bang For Buck
Author
Discussion

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
Is anyone interested in looking at a performance & economy index for measuring cars, but biased towards economy? I was thinking about this today as my little Fiat does 52mpg on a run yet has near to 300 bhp. I tried creating a little Excel spreadsheet and although it's simplistic it does seem to work.

Firstly calculate BHP per metric tonne, divide it by best MPG and divide that by 1000. An example:

Abarth 500 G-Tech
Weight: 1035KG
BHP: 288
BHP Per Tonne (288/(1035/1000)) = 278
Best MPG: 52.5
Bang for Buck: 278/(52.5/1000) = 14.61

I've compared this to a couple of other cars I've owned with similar figures and it does seem to work.

So, who has the car with the best "bang" (power) for the "buck" (economy) - ??

And, who has the worst non Eco car out there? LOL I fancy this might be a more popular way of looking at these numbers!! wink

My best is 14.61 and my worst car is 6.14.



Edited by Lagerlout on Tuesday 26th January 13:55

Diablos-666

2,786 posts

197 months

Tuesday 26th January 2010
quotequote all
300bhp from a fiat 500??? As you serious! The standard 500 car only has 150bhp so how have you doubled this?

If it has 300bhp, which i doubt, then there is no way it will do 52mpg! im sorry but NO!

Trolls Royce

4 posts

190 months

Tuesday 26th January 2010
quotequote all
no one cares

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
This wasn't about my car really lol, but here's the proof over about 150 miles on the French motorways! Seriously, this is a 1.5 litre engine and off boost it just doesn't use petrol!



blindswelledrat

25,257 posts

251 months

Tuesday 26th January 2010
quotequote all
By coincidence I was in the middle of doing a similar one.

MPG times Wheel diameter plus number of gears divided by oil capacity to see what comes out best.


blindswelledrat

25,257 posts

251 months

Tuesday 26th January 2010
quotequote all
This thread is actually insane.

beano500

20,854 posts

294 months

Tuesday 26th January 2010
quotequote all
Lagerlout said:
... French motorways! ...
blindswelledrat said:
This thread is actually insane.
Correction: "In Seine"....

Crusoe

4,110 posts

250 months

Tuesday 26th January 2010
quotequote all
A caterham with a very high bhp/ton will usually still return 40mpg if just cruising about which would also score very high.

400bhp/ton and 40mpg = 16

Some high tuned oil burners might also mess up your calculation with a high best mpg.

mk1salami

228 posts

207 months

Tuesday 26th January 2010
quotequote all
Bikes will win this one.

06 ZX6R 136 bhp
164kg (dry weight)
824bhp / tonne
42 mpg



Edited by mk1salami on Tuesday 26th January 14:12

5pen

2,064 posts

225 months

Tuesday 26th January 2010
quotequote all
Lagerlout said:
Bang for Buck: 278/(52.5/1000) = 14.61
Edited by Lagerlout on Tuesday 26th January 13:55
Bang for Buck: 278/(52.5/1000) = 5295 on my calculator.

pacman1

7,323 posts

212 months

Tuesday 26th January 2010
quotequote all
Is the OP running NOX? I think he's got a hundred brake too many there.

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
What, are you jealous you bought the wrong car?

I posted this thread because there have been lots of discussions on here about small(er) capacity turbo engines being the wave of the future. Look at the new McLaren and news coming from both Lambo and Ferrari.

If you're not interested in the thread don't post!

10 Pence Short

32,880 posts

236 months

Tuesday 26th January 2010
quotequote all
blindswelledrat said:
By coincidence I was in the middle of doing a similar one.

MPG times Wheel diameter plus number of gears divided by oil capacity to see what comes out best.
I was going to do similar.

Engine size X Number of 'What Car for £xx threads in General Gassing X Number of barried Mk4 Golfs at the Sunday PH meet X 7.


mk1salami

228 posts

207 months

Tuesday 26th January 2010
quotequote all
There's no reason he's not getting standard MPG in his car. Off-boost if the ECU is targetting a normalish air / fuel ratio (~15.5 afr) then the car won't be pumping in any more fuel than normal. I'd imagine the turbo would be pretty big to reach 300hp so it'll be pretty easy to drive out of boost on the motorway.


Edited by mk1salami on Tuesday 26th January 14:16

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
mk1salami said:
There's no reason he's not getting standard MPG in his car. Off-boost if the ECU is targetting normalish air / fuel ratio then the car won't be pumping in any more fuel than normal. I'd imgaine the turbo would be pretty big to reach 300hp so it'll be pretty easy to drive out of boost.
Exactly. Also, the car has lightened clutch, flywheel, rods and pistons. So it takes less HP than even a std car to keep it ticking over.

Justayellowbadge

37,057 posts

261 months

Tuesday 26th January 2010
quotequote all
I do like the idea of a 300 bhp 500.

Is there enough room in the boot for my unicorn?

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
LOL

http://www.pistonheads.co.uk/gassing/topic.asp?h=0... 500

Dyno for the doubters

Anyone else care to front their figures?

pacman1

7,323 posts

212 months

Tuesday 26th January 2010
quotequote all
Lagerlout said:
What, are you jealous you bought the wrong car?

I posted this thread because there have been lots of discussions on here about small(er) capacity turbo engines being the wave of the future. Look at the new McLaren and news coming from both Lambo and Ferrari.

If you're not interested in the thread don't post!
So you're getting 300bhp out of a turbo'd up 1.5 then. cool

Lagerlout

Original Poster:

1,812 posts

255 months

Tuesday 26th January 2010
quotequote all
mk1salami said:
Bikes will win this one.

06 ZX6R 136 bhp
164kg (dry weight)
824bhp / tonne
42 mpg



Edited by mk1salami on Tuesday 26th January 14:12
Oh yes, 34.83.

Diablos-666

2,786 posts

197 months

Tuesday 26th January 2010
quotequote all
mk1salami said:
There's no reason he's not getting standard MPG in his car. Off-boost if the ECU is targetting normalish air / fuel ratio then the car won't be pumping in any more fuel than normal. I'd imgaine the turbo would be pretty big to reach 300hp so it'll be pretty easy to drive out of boost.

Exactly. Also, the car has lightened clutch, flywheel, rods and pistons. So it takes less HP than even a std car to keep it ticking over.

> Well all i'll say is prove it! 288bhp is quite an acurate figure so surely you would have got that reading from a dyno!? So scan it in and prove me wrong!

Your thread is named - Bang for your buck - what has mpg got to do with it? Surely bang for your buck is bhp/cost of car = bang for buck!

I would suggest the best car for this is the s/c Monaro VXR. 500bhp for less than £20k mpg a nice 6mpg smile