A few days ago, I received an email from a reader (thank you Richie) asking to know more about Triumph TR4/TR6 wheel & tire sizing as fitted to our cars. I thought this might be helpful for others so I decided to take a few pics and show you what we have installed.
My Cousin’s TR4 Wheels and Tires
The email from Richie mentioned he had never seen a TR4 with 16″ Panasport wheels as in the case of my cousin Jim’s TR4. The wheels are Panasport in the “standard” size for a TR6: which is 16 x 7 inch, zero offset as indicated by the following picture from taken from one of the boxes.
Richie also mentioned in his email that this wheels size would be too wide for a stock TR4 because the wheel would make contact with the leaf spring. I suppose this is correct, however in our case this is not an issue because the rear suspension on my cousin’s TR4 is using coilovers instead of a leaf spring. As seen in the following picture the wheel/tire package fits very nicely without the need for any sort of wheel spacers. On closer look on the picture below, the rear wheel looks a bit “off” but that is just because of the way the surface is below the tire. There is a dip in the driveway ahead of the concrete pad.
Here is a picture from the back of the car just to show the profile. It is a little dark – sorry about that, I took this with my cell phone – but you can see the tires don’t stick out too far out from the fender edges.
So now lets talk about tire size. My cousin decided on a set of Bridgestone Turanza 185-55 R 16 as show below, on all four wheels. They are a little narrow, but they work well. If I am not mistaken, these tires came from a local Discount Tire store.
bowtie6‘s (TR6) Wheels and Tires
I have the same wheels as fitted to the TR4 on my TR6. However, the tire sizes are quite different. My first attempt was a set of matching Kumho 215-55 16′s. This worked very well and gave bowtie6 a very aggressive look. However, the front tires in this size were just too wide and on cornering I heard the edges of the tire digging into the front fenders. I did not want to push my luck and have further problems so I bought a set of matching Kumho 205-55 16′s for the front.
This is what the 205-55 16′s look like on the front:
Here are the rear 215-55 16′s:
And finally, what this combination looks like showing the profile:
The Kumho’s have been very good and have lasted about as long as you would expect from a “summer performance” tire. When new, these tires were very soft and sticky, however after almost 18,000 miles they are now showing quite a bit of wear. They are also much harder and need replacing. More than likely I will be ordering a new set of BFGoodrich tires, just like the ones I recently bought for my Honda S2000 and they were sourced from The Tire Rack. They are also “summer performance” tires and I anticipate good service from them.
Just as in the case with my cousin Jim’s TR4, my frame has coilovers and clearance is not an issue. Finally, bowtie6 does not use any form of wheel spacers.
What about size for the next set of tires? Well, I have been struggling with this a bit. The staggered 205/55 front and 215/55 rear gives the car just a tad of rake that I really like. The downside is not being able to rotate tires. So the question is whether to go for the staggered look or just buying four 205/55 16′s for all corners. Stay tuned, I’ll have an update when I make up my mind!
Final Thoughts and Considerations
Please keep in mind as you study these pictures that we have custom made frames under out cars. The frames and suspensions were specifically designed in order to give the necessary room for clearance between the wheels and all other components without having to resort to dreadful spacers.
As a side note though, I did use the staggered setup along with the Panasports on my TR6′s factory original frame before it broke. In the front though, the upper “A” arms had to be trimmed just a tad in order to clear the wheel weights on the front wheels. The rears though, fit perfectly with the stock TR6 trailing arms. So a 16 x 7″ Panasport will fit on a TR6.
Another trick that is not easily visible is the way both TR4 and TR6 body shells are mounted on our frames. You see, we made spacers in order to adequately raise the body just a small amount in order to make things line up properly. This required a little “thinking outside the box” but the end result turned out very nice indeed.
And there you have it. If you have any questions, suggestions or comments they are all welcome. Just fill in a comment below and I will be happy to elaborate some more.