There are a lot more T rated tires available in those sizes than H rated. If you don't plan on driving at sustained speeds in excess of 118 mph then T rated should be fine. They may also be a bit lighter.
As far as I understand in the UK we have to fit tyres to maximum design speed of the vehicle, not the speed we intend to drive nor the legal speed limit of 70mph.
Many thanks for your comment
I'm not sure that is the case but I'm open to correction.
The reason I say that is because several years ago Graham Arnold, the main guy behind Club Lotus, took this issue up because it was becoming impossible to find H rated tyres in suitable sizes for the Elan. Standard size was 145/80x13 with the Sprint coming in at 155/80x13 and you can imagine how hard it was to find an HR tyre at 145 with an 80 series profile. I'm guessing this was the 1980s or it may have been the early 90s, I can't remember exactly.
Graham sadly died several years ago but not before sorting the issue out with insurance companies, etc. The upshot was that you could fit a tyre that's road legal for automotive use even if it was a lower speed rating. That was pretty much what everyone was doing anyway because I can certainly remember when there were no HR rated 145x13 SP sports on the market at any price. What you couldn't do was fit something of the right size that wasn't designed for automotive use - like something for a caravan or trailer for example.
There's good reasons to fit the appropriate speed rating if you can do so, the carcase is likely to be stronger (heavier ?) and it might even have slightly stiffer sidewalls - that's a guess, I'm no tyre expert. But many folks (including me) accepted that a T rated tyre was fine for road use in light of our maximum 70mph limit. When I ran standard tyres on the Europa I'm pretty sure mine weren't H rated and the Elan ran on S rated tyres until recently.
