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TR2/3/3A TR3 Tire Sizes

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JFS

JFS

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The 165 HR 15 Michelins on my 58 TR3A are twelve years old and need to be replaced because of their age. The wheels are KN J6 knock off alloys. I drive the car in a fairly spirited manner and would like to upgrade to a more modern tire. Since I have calibrated the speedometer with a ratio box after installing an A overdrive, I would like to maintain the same tire diameter as the 165s which is 25.6". I would also like to increase the width beyond their 6.5". The 205 65 HR 15 has a diameter of 25.5" and a width of 8.2", but I don't know if it will clear the TR3's fender wells. Anybody running any wide tires on their TR3s? What sizes clear? Any concerns about suspension /steering component capabillity?

I have owned my 58 TR3A for 25 years or so. Its basic resto was done in the early 80s, which included some engine mods: Twin Weber DCOEs, Elgin cam, milled head, chrome moly pushrods, stainless steel valves, exhaust header, Mallory dual point ignition, and harmonic balancer. About eight years ago I added Cambridge highlift roller rockers which gives me .427 lift at the valves. I have driven this car with its modified engine on numerous long distance trips with few problems.
 
I have never owned a tr3, but as far as width for any tire, the sidewall of your tire should not bulge wider than the width of your wheel rim and as to your coments about your engine mods, what kind of gas milage are you getting with this setup? I have been told that those type of webers can be very thirsty. Also, what would you estimate your horsepower to be?
 
Gas mileage depends on the weight of the foot on the accelerator pedal. On highway trips I usually got in the 20s, but I haven't figured it recently. I do remember getting consistenly in the 30s years ago before I modified it. I have no idea as to horespower; Classic Motorsports Jan issue dynoed a similarly modified engine (without Webers or roller rockers) at 101.6 actual at the wheels at 4700 rpm. I would guess mine to be in that neighborhood.
 
I don't think I've ever seen a properly mounted tire that had a sidewall narrower than the rim. Sure would make it easy to get curbrash! Check on Tire Rack's website, you can pull up specs of each manufacturers tire and compair them with what you have. They will have listed rolling diameter, tread width, section width (sidewall width), and wheel recomendation. Looks like a 195/65 15 like the Bridgestone RE92 with a diameter of 24.7 and a section width of 7.7 on a 6.5, which would be 7.4 on a 6, would be the closest.
 
I dont think you will be able to use the 205/65's on a tr3 with out some bodywork....the 195 might do OK, for sure the 185/65 will work well. I use Yoko's and am well pleased so far.
MD(mad dog)
 
I had 205/55 on my 59 TR3A, and they rubbed lightly on the rear fenders. Really depends a lot on what wheels you chose ... I was using 5.5" TR6 wheels which have a bit much offset. 5 cm less and the tires wouldn't rub the fenders, but I think would still clear the springs (although not by much).

Randall
 
Hi Ya'll , Does anyone know of a modern tire size that will fit in the spare tire compartment of the TR3A ? None of the tires I have will go in there .
Thanks and Best Regards , Bob
 
My TR3A is an early 1959 with vin TS42756L. The tire cubby is tight and I was running 60 spoke wires with Michelin X 165SR15’s. Of course the 5th wheel would not fit. I converted to splined alloys which made the challenge even more difficult. I needed a splined spare. Found a 48 spoke wire in reasonable condition, had it soda blasted and powder coated. Bought a Firestone F560 which is a 145SR15 and tube from Coker Tire. It fits nicely with a little giggling over the securing strap. If I ever have to use it, the flat on the alloy wheel will have to be strapped to the luggage rack. If you are running stock steel wheels that tire mounted should fit. Good luck

Frank D…….
 
I have a 1961 TR3A and am running 165/80R15 on original steel wheels. The spare fits in the cubby but is a close fit. I put a towel under it and a strap around it to give me something to grip when I pull it out.

David
 
I am led to believe that post TS60000 TR3A’s had a slight bigger tire cubby. That may be why the 165 80R15 fits.
Frank D…
 
IMHO... the perfect size tire for a TR3 is a 195/65/15. I run TR6 wheels with 0 offset. No rubbing... fills up the wheel well perfectly.

Tire size.PNG
 
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