Most bhp per mpg
Discussion
Melvin Udall said:
The problem is that when a car is using the BHP figured that folks will quote, it won't be doing anywhere near the MPG they quote! 
True, but where's the fun in that?My turbo MX5 has ~255rwhp which would be around 290 at the crank, and the best fuel economy I've had from it was 47mpg on a boring open road cruise.
So 290/47 = 6.17
Hang on, doesn't that method of calculating completely defeat the point? Because the lower the mpg is the higher the end figure will be, if my car only did 1mpg then it would be 290.
How about bhp*mpg, giving:
MP4-12C: 592*24 = 14208
My MX5 turbo: 290*47 = 13630
My Legacy GTB: 276*33 = 9108
RX-8: 231*25 = 5775
Obviously given the order of magnitude difference between the numbers bhp will be a bigger factor in most cases.
Prius: 134*76 = 10184
(76 claimed extra-urban test figure on wikipedia, no idea if it represents real world or not)
Edited by GravelBen on Sunday 13th November 07:07
GravelBen said:
Obviously given the order of magnitude difference between the numbers bhp will be a bigger factor in most cases.
Prius: 134*76 = 10184
(76 claimed extra-urban test figure on wikipedia, no idea if it represents real world or not)
The new one may be quoted at 76mpg but its real world economy is pretty much the same as the previous one but it is more quiet at speed and the front looks better.Prius: 134*76 = 10184
(76 claimed extra-urban test figure on wikipedia, no idea if it represents real world or not)
A car can have 400bhp or a turbocharger or whatever but on the fuel economy tests they're geared up to try to not use either.
Interesting question.
I've been playing in a spreadsheet trying to fine something that will give me a "best fun car that's also practical" kind of thing, so a Prius with crap power wouldn't do well, and also a 1000bhp, 1mpg car doesn't do well.
= (MPG * BHP * BHP) / 10000
gives
MP4-12C: 24/592 = 841.1
MX5 turbo: 47/290 = 395.3
Boxster S 34/320 = 348.2
Legacy GTB: 33/276 = 251.4
Prius: 76/134 = 136.5
RX-8: 25/231 = 133.4
1000bhp,1mpg = 100
(i think we need to use typical MPGs, not "the highest figure I've ever seen whilst doing 56mph down a steep hill, the wind behind me and 6 inches from the back of a lorry" mpgs!)
I've been playing in a spreadsheet trying to fine something that will give me a "best fun car that's also practical" kind of thing, so a Prius with crap power wouldn't do well, and also a 1000bhp, 1mpg car doesn't do well.
= (MPG * BHP * BHP) / 10000
gives
MP4-12C: 24/592 = 841.1
MX5 turbo: 47/290 = 395.3
Boxster S 34/320 = 348.2
Legacy GTB: 33/276 = 251.4
Prius: 76/134 = 136.5
RX-8: 25/231 = 133.4
1000bhp,1mpg = 100
(i think we need to use typical MPGs, not "the highest figure I've ever seen whilst doing 56mph down a steep hill, the wind behind me and 6 inches from the back of a lorry" mpgs!)
GravelBen said:
Melvin Udall said:
The problem is that when a car is using the BHP figured that folks will quote, it won't be doing anywhere near the MPG they quote!
True, but where's the fun in that?My turbo MX5 has ~255rwhp which would be around 290 at the crank, and the best fuel economy I've had from it was 47mpg on a boring open road cruise.
So 290/47 = 6.17
Hang on, doesn't that method of calculating completely defeat the point? Because the lower the mpg is the higher the end figure will be, if my car only did 1mpg then it would be 290.
How about bhp*mpg, giving:
MP4-12C: 592*24 = 14208
My MX5 turbo: 290*47 = 13630
My Legacy GTB: 276*33 = 9108
RX-8: 231*25 = 5775
Obviously given the order of magnitude difference between the numbers bhp will be a bigger factor in most cases.
Prius: 134*76 = 10184
(76 claimed extra-urban test figure on wikipedia, no idea if it represents real world or not)
Edited by GravelBen on Sunday 13th November 07:07
Do you have a thread for your '5?
robotrhys said:
Quoted manufacturer engine bhp divided by its best possible economy figure.
Using best economy figures I've obtained over distance, cruising at a displayed 75-80mph.E36 323i (manual): 170 / 43 = 3.95
E32 750i (auto): 295 / 28 = 10.54
Using average figures over the course of ownership:
E36: 170 / 32.4 = 5.25
E32: 295 / 20.3 = 14.53
So essentially you want to know what car has the best brake specific fuel consumption?
Measuring something 'per mpg' is a rubbish idea: you are essentially multiplying power by fuel consumed (dividing by miles per gallon is equal to multiplying by gallons consumed and dividing by miles travelled) so favours inefficient cars.
Measuring something 'per mpg' is a rubbish idea: you are essentially multiplying power by fuel consumed (dividing by miles per gallon is equal to multiplying by gallons consumed and dividing by miles travelled) so favours inefficient cars.
Hm, can we get the vehicle weight in there somehow? Perhaps bhp/kg * mpg?
Hm. Nice table, but this needs to be tweeked. Didn't want to prove that
.
| Model | Weight (kg) | Power (PS) | Consumption (MPG) | Index |
|---|---|---|---|---|
| Swift Sport 2011 | 1040 | 136 | 44.1 | 5.77 |
| Elise 2011 | 876 | 134 | 45 | 6.88 |
| 123d | 1415 | 204 | 55 | 7.93 |
Hm. Nice table, but this needs to be tweeked. Didn't want to prove that
.Edited by Kolbenkopp on Sunday 13th November 17:57
Roger Dodger said:
Benjamin!
Do you have a thread for your '5?
Uh, only a really old one I started when I first got it!Do you have a thread for your '5?
http://www.pistonheads.com/gassing/topic.asp?h=0&a...
Have made a few further tweaks since buying it but nothing groundbreaking - sticky tyres, rollbar, bucket seat, ride height and alignment. Great fun but its actually up for sale now as it just isn't getting the use it deserves.
http://vimeo.com/15896697
Crombers said:
I'm always quite pleased to see 30mpg on a steady cruise out of the 500+BHP 514lb/ft 1950kg BMW 7 series.
Hats off to Alpina!
I love your car, very nice indeed! I don't like the looks of the normal 7 of that generation but the Alpina version works well. Hats off to Alpina!
I once rushed from home to uni, 101 miles at 19.7 MPG - in a Toyota Yaris Mk1 1.0!
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