I think there's something to that, but I don't think they slowed down the X2010's acceleration. It seems like tires are staying hotter after breaking traction since the 1.07 update. Once they heat up, it's hard for them to get grip again, which messes up acceleration and handling until you can let the tires cool off a bit. I wouldn't be surprised if the X2010's tires are heating up more and losing their grip for longer periods of time.