Q is the speed rating for up to 99 mph, which is perfectly acceptable for the Z. Even if you were to go faster than that, the likelihood of you doing it for a sustained period is highly unlikely! However, be wary the 140/80 Q wears out a lot quicker than 130s in S (112 mph) and T (118 mph) ratings.

As for handling/confidence. In my opinion they're fine. Be aware that some people (me included) find that TKCs can induce a front end wobble on the Z, nothing scary mind, over 70 mph, particularly accelerating with a lightly loaded front tyre. This I found to be much worse with the 140 rear fitted and gets worse as the rear (both 130 and 140) squares off. Fiddling with pressures doesn't seem to cure it either. Don't expect them to handle, or last anywhere near as long as your Distanzias on the road!

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