They way I look at it is the bigger the gear with a given ratio it will have more punch. With the smaller spur the car never really seems to get out of the corner but once you put a larger spur on with the same final drive ratio the car seems to launch harder out of the corner.....and I dont think its faster out of the hole b/c the motor is moved a little further back now b/c of the larger spur. Yes a ratio is a ratio but if say you take your car with one set final ratio and it covers say 100 ft in 3 seconds with a speed of say 35mph at the end of the 100ft with a larger spur, then try a smaller spur at the same final drive and it covers the same 100ft in 3 seconds but does it at a top speed of 40mph at the end which one is faster? They both went the same distance in the same amount of time but one did it with a higher finishing speed. So what does it mean? Maybe at 50ft the larger spur was at a higher top speed then the smaller spur at the same distance so it would be faster there. This is all speculation on my part but it is what I belive what really happens. The only true way to test all this out is to get a "G-Tech" system for the car and see what its doing at a set distance with the same ratio's but with bigger or smaller spur gears.