So, today I got a set of 14" wheels for my Valiant that had 13" 165/80/13's on it. They are 195/75/14's. Two pairs of tires...one needs to be replaced soon, one pair practically brand new.

Anyway, my question is this. Does the difference in size affect anything besides the speedo reading? I went to a tire comparison thing online to try to find out how much bigger they'd be, and I had some blurb about changing to anything more than 3% bigger or smaller. I drove it around my cup de sac with the new wheels and tires...it stops and goes ok, but not sure if there's some obvious point that I'm missing.

_________________
65 4 dr. Valiant 200

I think that 3% rule is for tires mounted to same axel, and full time AWD cars. If there is much difference in circumference between two tires on same axel, differential will not tolerate constant difference in speed of rotation between both tires over life of tire. It is only deigned for when car turns, not full time rotation correction straight down the road.

That being said, you can get away with miss-matched circumferences for a short trip of say 50 miles, as in doughnut spare tire use.

One of the rear tires of our AWD 300C was molested (2â€￾cut in side wall) by my wife when she backed into one of the concrete 12â€￾ tall walls between doors before the garage was built during house con$truction. I had only used about one third of tread, and tire place wanted to install four new tires. I said two will do on same axel.

The car seems to be tolerating this, but at times sitting in traffic, at a light, I get a kick in pants feel like the transmission is shifting hard into first. I think it is just the back axel and front axels unwinding kind of like a limited slip will do if something is not quite right.

It is almost time to replace the two oldest tires, so I’ll probably bite the bullet and get four new tires, as it is a pain in the neck constantly having two worn tires and two good ones practically during the winter in these parts.

I’m not a big fan of mixing tire sizes and brands on a street driven conveyance. The engineers designed the chassis with all four the same, and sometimes putting a taller tire on rear and or different makes will upset stability of vehicle. Different side-wall sizes will effect ride and handling as that flexing provided by side wall is part of the suspension’s design.

Track use only car; that’s a different story, it’s specialized, do what you want.

My 2 cents
Bill

_________________
67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

If your has a 2.93:1 axle and was originally equipped with 6.50-13 tires (17 tooth speedo pinion), your P165/80R13 tires would have caused your speedometer to actually be about 6.7% slow at 60 mph. Switching to a the P195/75R14 would now cause your car to be about 1.8% fast with the speedo at 60 mph.

Speedometers can be out of calibration. The most accurate way to verify this would be to compare your car's odometer with a GPS odometer.

See Tire Upgrades.

Here's another Tire Size Calculator, just to play with more numbers.

On some of the AWD cars, not only is there a requirement for matched tires on each axle, but all around as well. In other words, they want you to replace tires as complete sets.

Kissing a curb and raising a blister? $$$$

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO

I'm just worried about the viability of 14" wheels and tires on a car (65 valiant) designed for 13". everything that's on there now is the same size, just curious about the effects. A gps would be a good test since I think the speedo works, but seems a bit wonky at higher speeds.

_________________
65 4 dr. Valiant 200

As long as the bolt pattern/hub center of the wheel are the same,the size of the wheel is meaningless. The car was not designed to have 13" wheels,thats just what the factory decided to put on there. 14" wheels give you a better tire selection,but even then no where near that of a 15" wheel.

I should have said "stock" instead of designed I suppose. That's why I wanted the 14"s...13" tires are pretty hard to find. I paid about $200 (including shipping) for the 13" tires I bought online...I paid $80 for the 4 14" wheels with 2 pairs of tires that hold air, one pair being practically brand new tread-wise. Yep, the 13" tires are going back.

_________________
65 4 dr. Valiant 200

The 17 tooth pinion will work fine with both P195/75R14 and P195/70R14 tires if you have a 2.93:1 axle. I would just replace the worn pair with tires comparable to the good pair. As long as you rotate the tires in pairs, your car should handle fine. After all, for us who live in northern climates, it was common to use snow tires on the back during the winter.

Eventually narrow 14" tires might become hard to find too. Upgrading to slider disc brakes will get you the more common 4½" BC so you can then easily use 15" rims.

15"s would be nice.

_________________
65 4 dr. Valiant 200

You can get SBP 15's+ from places like wheel vintiques,coys wheels,or even american racing. The style selection is rather limited though compared to LBP. Im sticking with SBP because I have a factory KH disc brake set up,but if you have drums now,I would suggest looking for the 73+ LBP disc brake set up as mentioned above.

The only concern I would have is that larger tires make the already inadequate drum brakes work harder (better grip & more leverage due to bigger diameter). I really don't miss my 9" drums at all.

_________________
63 Valiant Wagon
225 - 4 bbl

I've seen 14" tires on some rather recent chevies, so 14 should be fine for awhile....

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Remember, installed overall diameter is important to the effective gear ratio and speedometer reading. Rim diameter itself isn't.

I'm running 15's on my '64 Valiant, which came with 13's. I kept the overall tire height very close to the wheel/tire combination that was on it when I got it. The speedometer is pretty close, per GPS.

I went with non-stock rims for several reasons:
Better tire choice for my application 15 X 7 vs 13 X 4.5
Clearance for the late-A disk brake swap and possible upgrades from those.
Bolt pattern change required new rims

_________________
"When you find a big kettle of crazy, it's best not to stir it." - Pointy-haired Boss

1964 Valiant V200, 225/Pushbutton 904
BBD, CAI, HEI, LBP, AC, AM/FM/USB, EIEIO