You might want a larger size than the spec tire. Also, tire development continues, you might want the latest technology. Conversely, you might be cheap and not need the best tire.I've always wondered about this...
If Lotus worked with Yokohama to specifically produce a LTS version of the tires then why would you choose not to use the AD07's or A048's.
Or is a tire really just a tire...
Recalling the Top Gear episode where Clarkson complains of understeer on the stock Elise, till the Lotus company driver shows him how it's done – the Lotus driver basically said Lotus supplied small front tires so the average driver would not as easily get oversteer. He suggested that larger front tires could be supplied and would be appropriate for highly-skilled drivers.The touring (waits for slap) sized front tires are just too small. Why pay a fortune for 175 frons when most decent 205s will grip better.
I was curious about the same thing, and gave yokohama a call last week. The tech that I spoke with told me that although they appear the same visually, the are constructed differently. The LTS is constructed with 1 ply rayon and 2 ply of nylon, to disipate heat better, and the standard tire is made with 2 ply polyester, 1 steel, 1 nylon. It is also lighter by about .44 lbs. After talking to him, I feel better knowing I am not paying a bunch of extra money just to have LTS on the sidewall. At least there is some difference between the tires.I am not sure how the LTS is different from the regular yokos but I suspect it is a slightly thinner sidewall. In theory the lotus optimized tires should be the best, in reality there are better choices for many.