Yeah, sorry I misunderstood what you meant. My mental image of splines (few points, big curves) didnt fit with my mental image of lookup tables, but I see what you mean now.

I mean, its worth saying that interpolated look-up tables arent necessarily unrealistic, in this example they are probably more realistic. And they're probably faster than an equation as well. They just seem to lack elegance, and adaptability.

Quote from colcob :

And they're probably faster than an equation as well.

not really youll probably end up computing the splines every time you select the car and then theres a whole bunch of ifs to decide which spline to use for a given rev etc
and in the end its all equations either way