I havent had a chance to drive the speed 12 yet, but the speed 6 i didnt like at all, so a bigger/better version of that idoubt is better. *The best overall NA engine i think is the F090 open wheel car, *it has the best turning/braking capability, which is benifial on most races, except for the test track(limited speed), which you would need to set the gear ratios as wide as possible except for the 6th gear, keep it at 1.000 otherwise you will fail to accellerate when shifting to 6th gear.