R888 vs NT05
 

looking for new road/race tyres for my mx5. Either thinking of going R888's or NT05 on a 15x8 wheel. Does anyone have any reviews or anything to help the decision?
tyres will be 225/45 R15.

Neither.

NT01s.

for the road in winter? awesome

NT-01's will be better than either of your first choices. NT-05 is a street tire more so than a race tire it will last a bit longer if just driven on the street but suck at about everything else comparitively unless whatever racing your doing requires the manufacturers molded in tread wear rating to be above 160 or something. But in reality I dont think the tread lasts longer on the NT-05 with a treadwear of 200 vs the NT-01 or R888 at 100. The Toyo R888 nobody who seriously races seems to like. it seems like they screwed up the sidwall design or somthing when they tried to replace the RA-1. NT-01's are made in the same plant as the toyos and are believed to be the same compund with different tread and somhow slightly different construction NT-01, RA-1, and R888 are all very similar but somhow behave differently. RA1 starts out with more tread and will last longer on the street but at full tread overheats on the track and rubber tears off rapidly. they need to be shaved for the track where as NT-01's are moulded at the shaved depth.

The real answer is, "the stickiest tires that you are allowed to use by the rules that will last the whole race."

Winter street tires are not the same as summer race tires. I assume from your answer you used the word "race" in error and you just meant for doing casual track days.

ended up with NT01's Fun times ahead

Imagine that.

Enjoy your winter racing.