Tire Pressure

[AZ86Turbo]

Hoping for some help with tire pressure. My owners manual states 21 psi front/25 psi rear which seems low to me by normal standards. They are quoteing this pressure for the Goodyear NCT's that came on the car and that I should use that tire due to the fact that is developed for the car. The car has BFG Comp T/A's now so does that low (to me) tire pressure apply or is it something specific to Goodyear? As the tires will need replacing in the near future are their any recomendations on replacement. There seems to be few choices in the 195/60 15 - 235/60 15 tire size. Thanks

Doug

[lotusguy]

Hoping for some help with tire pressure. My owners manual states 21 psi front/25 psi rear which seems low to me by normal standards. They are quoteing this pressure for the Goodyear NCT's that came on the car and that I should use that tire due to the fact that is developed for the car. The car has BFG Comp T/A's now so does that low (to me) tire pressure apply or is it something specific to Goodyear? As the tires will need replacing in the near future are their any recomendations on replacement. There seems to be few choices in the 195/60 15 - 235/60 15 tire size. Thanks

Doug

Doug,

I have had the Comp T/A's and now run Dunlops on my '85 Turbo. In each case, I contacted the tire manufacturer and their advise was to go with the Factory air pressure of 21/25PSI.

Lotus derived this pressure to make the suspension work correctly and so should be followed. It should be noted that Lotus also calls for higher tire pressure if the car is being driven hard (Twistys) or tracked.

The current tire selection in 195/60 15 and 235/60 15 sizes is pretty bleak. I am running Dunlop SP Sport 8000 and love them. They are 'Z' rated, have a traction and temp rating of 'A' and a treadwear rating of 200.

However, to do so, I had to drop the aspect ratio to 50 series tires and also, I went with 205/50ZR 15 fronts and 245/50ZR 15 in the rears on the stock wheels. It is a great combination. The 205 fronts seriously reduce the car's tendency for 'understeer' and since the aspect ratio is a ratio of the tire width, they are almost the same size as the 60 series in the narrower widths.

There some trade-offs which are: 1. The top speed is slightly reduced (but who lives there anyway) 2. The speedo is slightly off, or I should say more off since Esprit speedos are usually 5 MPH slow of actual speed. These tires rotate 841 revolutions/mi. vs. 814 for the Comp T/A's in your size. (You can easily and cheaply have the speedo recalibrated). 3. The engine will run at slightly higher RPM for a given speed (very slight increase <100 RPM @ 70MPH in 5th, besides, I love the sound of the engine).

Given the current selection available, this is really the only tire to go with and the only Z rated tire in anywhere near the correct sizes the good thing is that it is an excellent tire and you'll feel the difference between them and the Comp T/A's immediately. Happy Motoring! Jim'85TE

[AZ86Turbo]

Jim,

Thanks for the tire help! It' good to know that the wider tires will fit on the stock rims. I really like the look of the stock rims (even though they are 15") and wanted some good tires when I had to replace them. When I got online at Tire Rack I was shocked at how few the choices were. I have to get out more! This ain't the 80's anymore. I'll set the tire pressure to the book like you recommended. Thanks again

Doug