Tyre Pressure

My MGB tourer is fitted with 175 x 14 tyres.
What tyre pressure should they be ?

Mo......................

My '76 sticker on the glovebox indicates 27 front, 31 rear. That is for 165R-14; I don't see any reason to change it for 175 or 185 tires. After all, it is the weight of the vehicle that is the biggest determining factor in optimum tire pressure.

whatever the tire manufacturer recommends.

x2 on the 27 for front and 31 on back. I adjust mine this way and it really does make a difference on how the car handles. I have the same size tires as you.

I got this information from the V6V8 forum. Those guys seem to use a lot of different tire configurations. Get some white shoe polish and strart with the recommended pressure
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[*] Using the shoe polish, make a heavy mark across the entire tread of all the tires..
[*] Drive the car
[*] Examine the white mark on the each tire.
[*] Not enough pressure - the center will remain white and the outside will be almost gone.
[*] Too much pressure - the center will be gone and the outside will remain white.
[*] Increase or decrease pressure until the mark wears evenly across the tire
[/list]
Be patience, this takes time and you may have to do it a few times. This technique gives you optimum rubber contact to the road. Don't know how it relates to comfort.

Those numbers sound good to me too. You could go + or - one or two pounds front or back to change the ride and handling a bit. From prior threads, a lot of people tend to run the back several pounds higher than the front, and I usually go with a difference of about 3 psi.

Drake
The pressures listed on the tire by the manufacturer are not recommended pressures, they are maximum pressures.

Pressure is set by tire construction, vehicle weight, driving style, environmental conditions and lots more. You will need to play with pressures a bit until you find what works best for you. Most people run 27-30 front, 29-32 rear.

The book show two sets of pressures. I believe the max load in the 27 fron and 31 rear and the minimum 20 front and 24 rear. I tried the 20/24 and the car was loose at high speed. Tighten up at 27/31.

Keep in mind that pressure recommendations from the 1960's and 70's won't necessarily be correct for today's tires. Generally speaking, 20 PSI is way too low to be running in a modern radial on an MGB.

I'm running 30 front/32 rear right now, with 175s. Feels fine, handles well, gas mileage is good.