((bhp/tonne) x mpg)) / price

[goodlife]

Looking for an econimic commuter car with a bit of poke, but price sensitive. Sound familar?

Creating a shortlist I keep drifting towards a 4-5 year old 320d/520d because they offer incredible mpg, not bad bhp and are under £9k these days. But that got me thinking whether there was a maths equation that could help shortlist potentials.

I'm thinking of taking bhp per tonne multiplied by mpg, then divided by price (new or second hand, doesn't matter).

((bhp/tonne) x mpg)) / price where the higher the number, the better the fit

eg. for 520d:
((177/1.585) x 48) / 8500 = 0.63

or Bugatti Veryon
((1001/1.888) x 16) / 1000000 = 0.008

Does anyone have the available data to run this through every car ever made to what's top???

[Byard]

Heres my car, just for the fun of it

(250/1.485) * 42 / 4000 = 1.7676767676767676767676767676768

[p4blo32]

Interesting

350Z: ((280/1.5) * 28) / 8000 = 0.65

[kambites]

By that measure, you just want something very, very cheap and reasonably efficient. You'll easily find something which scores more than 10 if you look around.

[steviejasp]

My Cerbera......(411/1.2)x25/15000=0.57

Bargain! No depreciation!!

Edited by steviejasp on Friday 8th June 17:48

[joe_90]

Old clio cup

((172/1.05)* 40 )/ 1500 = 4.36

[kambites]

joe_90 said:

Old clio cup

(172/1052)*1500 = 245

You paid £1 for it and it does 1500mpg?

[joe_90]

kambites said:

joe_90 said:

Old clio cup

(172/1052)*1500 = 245

You paid £1 for it and it does 1500mpg?

haha.. no, i missed one step out, went back and edited it

[DonnyMac]

Ariel Atom ((300bhp/0.5tonne)*30mpg)/~£35,000= 0.514

It's got to be on the list surely

[V88Dicky]

(149/1.237) * 45 / 1800 = 3.011


2001 Toyota Avensis 2.0vvt-i

[ThatPhilBrettGuy]

A quick look in the classifieds shows Volvo T5's available around £800 giving a ~3.9.

It's a good idea, but like all equations that have no 'nice' factor it's not going to work

Didn't stop me doing my cars though

GT - 0.066
Noble - 0.34
Alfa - 0.27

[goodlife]

Ok, so the equation was flawed in 2 ways (and many many more I'm sure). Lets take Price and some sort of brand power for now.

Price: let's assume the car has to worth over £2k, else it's likely to be a piece of rubbish and not be able to do the commute part reliably.

Brand power: we'll add another subjective element, on a scale of zero to 5, with 5 being the most wanted and 0 being a Trabant.

Also on bhp, you need to use the combined figure.

So revised equation is

(((bhp/tonne) x mpg) / price) x Brand Power

[kambites]

How about this:

http://pistonheads.com/sales/3965818.htm

(170/1.2)*25/675 = 5.3; this being PH, BMW has got to be at least a 4 so that makes about 20 or 25 once you add that.

[DonnyMac]

DonnyMac said:

Ariel Atom ((300bhp/0.5tonne)*30mpg)/~£35,000= 0.514

It's got to be on the list surely

*5 = 2.57

[Rovinghawk]

Saab 9-3 Aero with stage 1 tune

((250/1.7)x36)/4000=1.324

Brand rating of 4? 5.294

RH

[Vitorio]

I think i just won the thread

((55/0.735)*47)/350=10.04

A '96 Fiat cinquecento sporting. Fuel consumption was a fairly conservative guess backed up by spritmonitor.de. Also the price was as low because of a headgasket failure, but i fixed that myself for just parts cost, and while doing that swapped in a better camshaft/throttlebody for added HP.

[john2443]

205 diesel, £500, 55mpg, rating 8.8!

Probably not the answer you want to get!

edit - or Metro diesel, probably an even better figure!

[Astra Dan]

Of course this is relative:

My GTE:

(156/1(x36))/£175

32.09.

[Raize]

Porsche 924...

(125/1.040) * 34 (apparently) / 650

= 6.287... not so bad.

I think we need some co-efficients for this formula, however.

Edited by Raize on Friday 8th June 20:18

[Synchromesh]

'03 Volvo S60 T5

((bhp/tonne) x mpg)) / price
(250/1.44) * 30 / 2750 = 1.89

(((bhp/tonne) x mpg) / price) x Brand Power
((250/1.44) * 30 / 2750) X 3 = 5.68

ETA: The 'revised' equation.

Edited by Synchromesh on Friday 8th June 21:15