Technical Tire pressure guides

[S854]

I’m just getting to know my new toy… out playing in the garage, fiddling with minor tweaks… so I thought I’d check the tire pressure… and I have no point of reference…

I found these references from Longstone tyre and Pirelli.

23 psi front/23 psi rear

Is this about where everyone is running their 165 r13 tires?

 

[gengis]

I tend to run the fronts at 28psi, I prefer the slightly lighter steering feel...tire size 185 x 14.

 

[124BC1]

For a Fiat 124 AS Spider running 165 - 13" radial ply tires the Fiat factory manuals specified 22.75 lb/sq.in (this was Fiat's conversion from 1.6 kg/sq.cm), front and rear. I noticed your car is fitted with Michelin XAS 165HR13, (i.e. equivalent to original fitment) so 23 psi all round should be fine.

As regards the figures of 23F/26R shown in the Michelin list above for the 124 Coupe, the Fiat 124 AC Coupe is longer and heavier at the rear than the 124 Spider, resulting in the tire pressures being 23 psi front and 26 psi rear.

 

[S854]

For a Fiat 124 AS Spider running 165 - 13" radial ply tires the Fiat factory manuals specified 22.75 lb/sq.in (this was Fiat's conversion from 1.6 kg/sq.cm), front and rear. I noticed your car is fitted with Michelin XAS 165HR13, (i.e. equivalent to original fitment) so 23 psi all round should be fine.

As regards the figures of 23F/26R shown in the Michelin list above for the 124 Coupe, the Fiat 124 AC Coupe is longer and heavier at the rear than the 124 Spider, resulting in the tire pressures being 23 psi front and 26 psi rear.

23 psi… just didn’t sound like enough… I keep forgetting how light these cars are…

On a side note, when it comes time to replace these tires, 165/70 and 185/70 are readily available… 165/70 is pretty close to original… 185/70 will fit on rims 4.5 - 6 inches… the Cromodora, at 5”, fit right in there…. It will the 185 fit the car without rubbing?

My speedo is roughly 5 mph optimistic… 60 mph GPS, 65 mph on the dial… I’m thinking with the slightly larger diameter of the 185 the car may gain in road speed vs speedo reading…

 

[124BC1]

-----------------------------------------so I thought I’d check the tire pressure… and I have no point of reference…

I found these references from Longstone tyre and Pirelli.

23 psi front/23 psi rear

Is this about where everyone is running their 165 r13 tires?

@S854
Here's a glovebox 'Capacities decal' I've just seen online for the 124 Spider BS1 (the model after your AS1 but afaik similar in weight), which gives 26 psi F & R as the correct tire pressures for 165 HR 13 tyres.

 

[S854]

Thanks, BC… my AS has a replacement 1608 engine (code 125BC000) … I’m guessing the capacities are very similar to the BS label…