TR6 just bought a 74 TR6 with over drive..which size tires would be best

really want a nice tire, more of a low profile tire. also thought about lowering the car a inch or two any suggestions on that would be appreciated.. peace happy hunting.. Nico triumph guy now lol :highly_amused:

You need to decide how much you want to change your gearing and your ground clearance. There are several sites that give comparisons between different tire sizes. https://www.discounttiredirect.com/direct/infoTireMath.do

I originally ran 185/80-15s on 6" rims on the 4A which gave 25mph/1000 rpm in overdrive with a 4.1 diff. You probably have a 3.45. I have changed to 195/65-15 Michelins which have dropped the gearing 7%. The car now feels under geared on the highway. It is also 3/4 inch lower. I have to decide whether I go back to 185s or change to a 3.7 diff. 205/65s are very popular here because they are the normal size for Fords and Holdens so they are cheap and there are plenty of different brands and they are the same diameter as the original 165-15s. A mechanic friend recommended NOT going to wide tires as the rear suspension camber change lifts them off the tarmac and gives LESS adhesion than a narrow tire. Good luck.

Be careful about lowering a TR6. They don't have a lot of ground clearance to begin with and if you decide to add an aftermarket exhaust your potential to bottom out on curbs and speed bumps will be significant. That said there are aftermarket springs that will lower the ride. I wouldn't do it if I were you but I'm not you

Good luck!

I'm running Kumho 205/70-15s on the TR6 and am happy with them. I also use that brand on a 280zx and a Mustang (all different sizes, of course) and they work very well on all of them. I second the warning about lowering the car too much. I put shorter springs and 60 series tires on the TR8 and paid the price when they installed speed bumps in the neighborhood.

I also have 205/70s on stock wheels, primarily (or at least initially) because of they way the fill out the wheel wells. Which is also a common dislike of the size. I've come to appreciate them for their precision and stability, at the cost of a slight loss of nimbleness. But then that could be the tires...Bridgestone something or others.

205/70-15 is probably the best choice if you want to stick with the stock 5.5" wheel width or a 6" wheel width. Using the non-Java script miata.net tire calculator ( https://www.miata.net/garage/tirecalc.html ) change the stock size to 185/80-15 and then use 195/70-15, 205/70-15, 215/65-15 in the tires to compare box.

It will come back with the 185/80-15 showing 757 revs/mile, 195/70 showing 783 revs/mile for a -3.4% difference, the 205/70 showing 767 revs/mile for a -1.3% difference and the 215/65 showing 776 revs/mile for a -2.4% difference.

While the 195 and the 205 section width tires seem reasonably happy on a 5.5" wide wheel, the 215 section width needs a 6" wheel width as a minimum. Due to the difference in backspacing, even at the same offset, the wider wheel and tire will stick outboard a bit more than the stock wheel and I have seen some front fender clearance issues associated with the 215/65-15 and 6" or wider wheels on a TR6.

My car has Goodparts 1 inch lowering Springs installed. I am running 16X7 Konig Rewind rims with 205/60 series Yokohama tires.





Cheers
Tush