It's 2005. Anyone racing has access to anything they'd like, should they wish to use it. All the car companies, and all the engine companies, have every opportunity to review the products that their competitors are making, using, and selling.
Fsturbo said it correctly - it's mostly the driver. All cars are not equal, and all engines are not equal, and probably that can be said for tires, clutches, shocks, bodies, and anything else you care to think about, but when it all comes together, the bottom line is what the driver can do with what he's got. There is no single definitioin for a car, or an engine, or anything else - it all gets tied up with setup, and how things are prepared for the race. If you take the "best" engine there is, and don't set it perfectly for the day's conditions, a driver who did this better will have an advantage. Ditto for a car.
Even if all the drivers were "equal", they all have different driving styles, and different preferences. At last year's worlds, there was a comparison made after the event between a car set up "like" Lamberto Collari likes them, and a car set up the way Josh Cyrul likes them. Josh's setup had lots of torque, and the driver had to regulate the trigger as throttle was applied. Lamberto's setup was such that you could just give full throttle, and the power would come on perfectly, as needed, no trigger modulation needed. As Josh put it later on, long after the event was over, there must be something to the way Lamberto configures things - just look at how many World Championships he's won.
When it comes to car setup, every book I've read emphasizes that a car that is "easy to drive" may very well not be the fastest. The fastest car might very well be one that's right on the edge, requiring expert skill to control. For the average racer reading all this, that's an important point. Most racers (should I say almost all racers?) don't have anything even close to the control of the experts, and would do better with a car that's "easier to drive". As they get better, they are in a position to handle a car that's closer to "the edge".
What I've been trying to do on the Starting Grid, is to explain things from the point of view of the "experts", but realizing that even they had to start out as beginners, to try to write things in a way that would benefit even the novice racer. As Ron Paris put it, a setup that worked for a beginner would be terrible for an expert - AND vice versa! All of this applies to the average guy, but take an expert, and give him an "average" car, and he'll probably put in a performance that would dominate almost any event.
What if you've got five, or ten experts, running together? If they were all "equal", then the slightest difference between their equipment could make all the difference. ...and their cars are not simply "which" car/engine/whatever they've got, but how it's set up for that particular track.
