Do they require a break in period for best performance. I have 8 new G+ cars. Drove one for a bit. Then tried another, then back to the first. The first one seems to be a little bit faster. True or just an illusion?

Yes, they run better when broken in. I usually run then without the rear end in for about one hour at 6V to start to seat the brushes on the comm. I know some people break them in much longer at even lower voltages, and some break them in at higher voltages. Whatever you do, some break-in is better than no break-in. Make sure you oil them before you leave them on the break-in setup for any length of time.

Thanks. What oil do you recommend?

I use the Champion Racing Oil sold by Parma, with a little Mobil 1 mixed in, maybe 10%. Which oil or blend to use is a very personal decision and there are an infinite number of variations and testimonials touting the effectiveness of one's special brand or blend over all others. The most important thing is to use whatever oil you decide to use very sparingly and in the right places. Investing in a needle oiler that allows you to target the specific spots that need lubrication. On the Super G+ cars I always remove the magnet clip so I can get a better angle on the rear bushing to apply oil. I put a tiny bit on the outside edge of the bushing where it meets the shaft and spin the motor by hand to work it in. The front bushing is recessed and harder to get at, but equally important not to overdo it because that's where the brushes are located. Don't overdo it and never let oil get on the commutator, motor windings, or brushes. You should put a tiny bit of oil on the front and rear axle where it touches the chassis. Don't put oil on the gears, it will just get slung off onto the track.

Thanks again!