Mathematic of sportscars

[gheba_nsx]

On an Italian/Swiss car forum it was discussed quite a lot in how to calculate the value of a sportscar using mathematic in a simple way... maybe too simple but the results are quite interesting anyway. A couple persons were discussing where to put your money if you wanted the maximum out of it, in the end it turned out to be a quite interesting exercise.

Both used and new cars where evaluated, of course used-cars gets a better "value" than new ones.

The five parameters used to come up to a result are:

- weight/hp --> (absolute power/torque were not considered, only in relationship to the total weight)
- weight/torque --> (absolute power/torque were not considered, only in relationship to the total weight)
- price (distance from the median price of 40'000 EUR)
- traction (rwd got 1 point, 4wd got 0,5 points and fwd got 0,25 points)
- weight (very important, even if weight is used inside the weight/hp and weight/torque, the absolute weight modifies the handling, braking and many other driving parameters)

In every category there was a winner that got 1 point, all other cars were scaled over the winner in a proportional way (example, the Viper won the KG/HP category and got 1 point, the RenaultClioSport had a weight/hp exactly the half of the Viper and got 0,5 points there).

All the five parameters were weighted the same, only the weight got a 1,25x advantage. The theoretical maximum is also 5,25 points.

These were the evaluated cars, already ordered for the result. The result is in the last column:

<pre>
Model Year Used/new Price Traction HP KG/HP Torque KG/TQ Weight TOTAL
MazdaMX5_1.9 ('99) U 13000 1 140 7.86 171 6.43 1100 4.26
LotusElise111S ('98) U 30000 1 155 5.10 175 4.52 791 4.04
OpelSpeedster ('00) N 29000 1 144 5.90 203 4.19 850 3.93
ViperSRT-10 ('05) N 75000 1 499 3.07 712 2.15 1532 3.93
HondaS2000 ('00) U 20000 1 240 5.04 218 5.56 1210 3.87
SpeedsterTurbo ('00) N 33000 1 197 5.00 250 3.94 985 3.81
IntegraTypeR ('99) U 13000 0.25 190 5.48 186 5.59 1041 3.78
CorvetteZ06 ('00) U 45000 1 379 3.72 485 2.91 1410 3.74
Nissan350Z ('05) N 30000 1 283 4.66 371 3.55 1319 3.72
LotusElise111R ('05) N 50000 1 190 4.60 181 4.83 874 3.67
BMW130i ('05) N 30000 1 258 4.84 300 4.17 1250 3.65
LanciaDeltaHFEvo ('91) U 15000 0.5 210 6.43 304 4.44 1350 3.61
MazdaMX5_2.0 ('05) N 25000 1 160 7.00 188 5.96 1120 3.53
Porsche GT3 ('99) U 55000 1 360 3.75 370 3.65 1350 3.53
Ferrari355 ('97) U 62000 1 374 3.61 363 3.72 1350 3.50
Ferrari360 ('01) U 73000 1 400 3.48 373 3.74 1392 3.46
Honda NSX ('93) U 33000 1 280 4.96 304 4.57 1390 3.44
Porsche993C2 ('96) U 35000 1 272 5.04 322 4.25 1371 3.44
Porsche996C2 ('02) U 50000 1 320 4.41 370 3.81 1411 3.39
Porsche GT3 ('05) N 100000 1 385 3.58 381 3.62 1380 3.38
BMW M5 ('05) N 98000 1 499 3.44 520 3.30 1717 3.34
MazdaRX-8 ('05) N 32000 1 246 5.33 216 6.17 1330 3.33
HondaS2000 ('05) N 40000 1 240 5.08 218 5.60 1219 3.33
BMW M3 CSL ('05) N 95000 1 355 3.90 370 3.74 1385 3.30
BMW M3 ('02) U 45000 1 338 4.64 365 4.30 1568 3.26
PorscheBoxsterS ('05) N 55000 1 280 4.88 309 4.42 1366 3.22
BMW Z4 ('05) N 45000 1 230 6.01 300 4.61 1382 3.16
PorscheBoxster ('05) N 45000 1 240 5.68 257 5.30 1363 3.14
LancerEvoVII ('01) U 30000 0.5 276 5.07 382 3.66 1399 3.11
Audi S3 ('01) U 22000 0.25 220 6.45 280 5.07 1419 3.06
Honda NSX ('05) N 89000 1 289 4.88 310 4.55 1410 3.04
ImprezaWRXSTi ('05) N 35000 0.5 276 5.22 394 3.66 1441 2.97
Audi RS4 ('01) U 40000 0.5 379 4.27 440 3.68 1618 2.95
LancerEvoVIII ('05) N 40000 0.5 276 5.11 392 3.60 1410 2.93
RenaultClioSport ('02) N 26000 0.25 169 6.20 203 5.16 1048 2.92
MiniCooperS ('05) N 24000 0.25 160 7.00 219 5.12 1120 2.88
MiniCooper ('05) N 18000 0.25 116 10.90 140 9.02 1264 2.73
Audi S4 ('05) N 47000 0.5 339 4.90 410 4.05 1661 2.70
HondaCivicTypeR ('05) N 30000 0.25 212 5.61 202 5.89 1189 2.70
AudiA3 Quattro ('05) N 38000 0.5 246 6.08 320 4.67 1496 2.68
AlfaRomeo147GTA ('05) N 35000 0.25 246 5.53 300 4.54 1360 2.61
AudiTT3.2Quattro ('05) N 45000 0.5 246 6.18 320 4.74 1520 2.57
AlfaRomeoGT3.2 ('05) N 36000 0.25 240 6.19 300 4.95 1486 2.44
</pre>


The prices for both used and new are for Europe (EUR) but the result wouldn't be that much different in the US, I imagine.

And again, the results are not really representative since so many irrational factors enter in a sportscar buying decision :wink: ...


EDIT: corrected a bit the formatting....

 

[NeoNSX]

Oh great gheba guru of mathematics on prime... what do all these magical numbers mean in simple English? The NSX wins right?

It a higher number better, or a lower number?
Also why do the LanciaDeltaHFEvo, Audi S3, etc. extraordinary high results?
What is the square root of pie? These are answers we need to know.

 

[NetViper]

Why is the NSX listed with 310 HP?

 

[heySkippy]

There's something screwy with the formatting of that grid. Makes no sense whatsoever.

 

[gheba_nsx]

Oh great gheba guru of mathematics on prime... what do all these magical numbers mean in simple English? The NSX wins right?

It a higher number better, or a lower number?
Also why do the LanciaDeltaHFEvo, Audi S3, etc. extraordinary high results?
What is the square root of pie? These are answers we need to know.

The more points, the better.

The Audi A3, even used, does not do wella t all!
The Lancia does well, since cheap, powerful and quite light.

The NSX does quite well too, if used. At 360 (used) or 911/993/996 (ised) level... [when new it gets a lot worse, but we knew that a new NSX is not a bargain in perofrmance/money]

 

[gheba_nsx]

Why is the NSX listed with 310 HP?

Actually the NSX has 280hp (used) or 289hp (new), 310 is the torque for the new one.

Damn formatting... I have to find a better way :tongue:

 

[NetViper]

Actually the NSX has 280hp (used) or 289hp (new), 310 is the torque for the new one.

Damn formatting... I have to find a better way :tongue:

Oh, is that 310 NM?

 

[gheba_nsx]

Oh, is that 310 NM?

Yes, we used DIN HP and NM, weight is in KG... you should have dumped those colonialistic english bull$#it when you dumped the king/queen centuries ago! :biggrin: :wink:

Does the table look more readable?

 

[NetViper]

Yes, we used DIN HP and NM, weight is in KG... you should have dumped those colonialistic english bull$#it when you dumped the king/queen centuries ago! :biggrin: :wink:

I agree 100%. I am from Canada. Where we use metric for most things. Coming here I had no idea what quarts were

 

[SCS2k]

I agree 100%. I am from Canada. Where we use metric for most things. Coming here I had no idea what quarts were

Quarts(z) is movement type for watches/clocks etc. :tongue:

 

[AU_NSX]

Excellent work!... Goes to support what Colin Chapman had said all along!

Yes, we used DIN HP and NM, weight is in KG... you should have dumped those colonialistic english bull$#it when you dumped the king/queen centuries ago! :biggrin: :wink:

Well this is one of those things that I can never understand... I live in one of "those colonialistic english bull$#it" countries that has not in fact "dumped the king/queen"... Yet we still adopted the SI units in 1966 at the same time as dumping the Pound and Pennies to accept the Dollar and Cents! To this day I cannot understand why any country would choose to stay imperial over metric

Does the table look more readable?

No.. But it would be great to have the spreadsheet!! :smile:

 

[W]

The point system has its issues. For example, it is extremely biased towards drag racing types of vehicles (an old Chevy Nova would top the list).

It was interesting to see the Miata on top. Go Miata!!!

 

[gheba_nsx]

Ok, I did put together a simple worksheet where everybody can choose their own priorities

The drag race people will give highest to hp/weight, the poor to price and we on the NSX :biggrin: :tongue:

Does somebody have a place to host it? It is less than 50kb...

Thanks!

 

[gheba_nsx]

If somebody is still interested, here's the file in Excel format... the price is still in EUR, the other parameters are in imperial format!

Quite easy to use: simply choose the parameters you prefer and give it more weight (default they are all "1" with a 25% preference on car weight --> set to "1,25").

Then choose the preferred traction, if you have no preference give "1" to all of them. If you prefer one over the other give it "1", "2" to the second and "3" to the third...

Press ctrl+a and it's all done!

It is easier to try it out than to explain!


enjoy
gheba

 

[CokerRat]

Like W says.... braking, handling, and refinement count for nothing. If they threw an early 90's Camaro Z28 into the comparo, it ought to walk off with the trophy.

 

[IsR]

Interesting infos

 

[Jin1976]

I would give 4wd 1 pt, rear wheel 0.5 pt and front wheel 0.25 pt.