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TR4/4A TR-4A tire size.

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Z

zoom1a

Freshman Member
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Hi.

Does anyone know the largest (widest) tire that I can fit on my '67 TR-4A? I've heard of guys going up to 205 75R 15 on TR-6's.

Thanks

Byron
 
There are so many opinions here.

BUT: Don't we need to first ask what the size of the wheel is?

On mine, a 4A, I think the wheel is only 4.5 inches wide, and I don't know, but suspect, that affects the tire size that safely can be used.

I'd like to know.
 
You can run the larger tires on you '67 but you will have to go with a wider wheel. I run 205/70 tires on 6"-wide rims on my TR6. (Panasports) However, IMHO, the big fat tires on a stock TR4 look funny. Watch for rubbing.
 
Hi There Zoom1a;

I carry "185s" as probably most TR4 owners do: The avg width is between 4-1/2" disc to 5" for wires: TR6s rims I believe are 5-1/2" on the width:

As mentioned previously; The Wheel Size is what determines your Max. Tire Size:

If you put TR6 rims on your TR4; Then you could go to "205s"; But, In my opinion; They just don`t look right or Good on a TR4:

Its really quite simple:

Regards, Russ /bcforum/images/%%GRAEMLIN_URL%%/banana.gif
 
195/65x15s are a popular size for the TR4 because they are close to the stock height (important for speedo calibration) and are beefy enough to be stable and handle well. I run 205/60x15s on 5.5 KN Minators. Ditto on the height and IMHO look great filling up the wheelwells. IMO the 165s just look too skinny.
 
Kentvillehound said:
On mine, a 4A, I think the wheel is only 4.5 inches wide, and I don't know, but suspect, that affects the tire size that safely can be used.
Click to expand...
That is exactly right. However, it's not a simple relationship only between wheel width and tire width; the sidewall height also makes a difference. So basically, for each tire size, there is a range of rim widths that are allowed.

One good place to look for that information is at
https://www.tirerack.com
since for each brand and size of tire, they (usually) list the "rim width range".

After a quick look, the widest tire I see suggested for 4.5" rims is 175. However, I have run 185/65 tires on 4.5" rims on my TR3A, and I can report that they worked quite well for me. Perhaps not as well as the same tire would have worked on wider rims, but much better than the old 165 tires did.

PS, I'm up to 205/55 tires on 5.5" TR6 rims. Had the car cornering so hard (before it was wrecked) that I needed stiffer sway bars to keep from hitting the suspension stops in hard corners. Of course, YMMV.
 
I bought a TR4 in 1968. The first thing I did was increase the rim width by 1 inch to 5 1/2 inches. I cannot remember the size of the Dunlops I put on, but guess they were 185's. The car handled very much better, and with the larger tires, it would do a little over 130 mph stock. For those of you who have gone fast with the top down, the wind over the windscreen begins to howl. Getting louder as you go faster.

Anyway, it was a little hard to get the car into a four wheel drift. But at 90 or so, the back would start to break loose, a jerk of the steering wheel, and voilĂ , a four wheel drift.

Ah, youth, how did I survive?
 
<div class="ubbcode-block"><div class="ubbcode-header">Quote:]

One good place to look for that information is at
https://www.tirerack.com
since for each brand and size of tire, they (usually) list the "rim width range".

After a quick look, the widest tire I see suggested for 4.5" rims is 175. However, I have run 185/65 tires on 4.5" rims on my TR3A, and I can report that they worked quite well for me.
[/QUOTE]

The folks at my tire shop plugged the numbers in the system they have and told me that for 4.5" rims the widest tire is a 165. I specifically asked about 175 since those were stock items and I would have bought them from him on the spot. He said he would not recommend it. As it was I had to go elsewhere to find 165, so I tend to believe what he said.

I am glad to hear that you were able to run the wider tires though, that is a good data point.
 
Thanks guys.

I would really like to get the 195's but I need to measure my wheels first. I would settle for 185's but I don't think that 175's would should enough improvement to be worth the cost.

Byron
 
Byron,
I would try to stick to no larger than the 185 with the 4.5" rim. You can get the 195/60 or 65's on but they lose their effectiveness when pinched on the smaller rim and will wear faster in the middle of the tread to boot. You might want to keep an eye out for some used 5 or 5.5" alloy
rims on ebay.
 
I have looked at this also for my tr4. My conclusion is this:
1. if you want bigger rubber than 165 you need wider rims.
2. if you do not want to flare your fenders you are limited.
3. if you don't want to have silly looking smaller OD tires
and stock ride height you are limited.
4. its hard to find performance tires with the same OD that
fit under stock fenders.
5. lowering the car and flaring fenders opens up different
possibilities.
My conclusion is a common one: use tr6 steel wheels and put on 195/65-15" tires (i am widening my tr4 wheels instead to 5.5" and am changing the offsets to get exactly what i want to suit stock fenders,4-pot wilwood calipers,internally vented rotors,aluminum hubs and tr4 hubcaps-yes i want it to look old and originalish)
Rob
 
The rule of thumb is that the rim width must be at least 70% of the tire width. That applies to aspect ratios 50% or greater.

In other words...

165 = 6.5" x 70% = 4.5" rim width
175 = 6.9" x 70% = 4.8"
185 = 7.3" x 70% = 5.1"
195 = 7.7" x 70% = 5.4"
205 = 8.0" x 70% = 5.6"
215 = 8.4" x 70% = 5.9"

Edit: I rounded off the figures...and I'm assuming that the tires are at least 50 series or greater.
 
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