[CMOTD]

Equal lane length does not guarantee equal lap times, other variables are at play. More by luck than judgement my home track has equal lengths but one lane is consistently slightly faster than the other. If I run the same car on both lanes at a set voltage (i.e no controller input) one lane is about a 10th faster than the other.

This partly due to the fact that I use one lane more often so more rubber has been laid down on it giving a grip advantage at certain points. Also, the longest straight gives an acceleration advantage to the car coming off the outside lane as it has gone round the corner quicker than the one on the inside of the bend. There is not an equal length straight elsewhere with the lane advantage reversed to even this effect out. The only way to negate this sort of thing would be to have a mirror image track.

Does it matter on my home track? Not in the least as it is only used for friendly competition and the lane advantage is marginal anyway but, as Tel says, you do have to avoid a large discrepancy between lanes or heat rotation just produces a draw.

Does it matter on a big club track? Indeed it does but that is a whole different can of worms!