Tires

[thirstysurfer]

I would like to upgrade the tires on my 1984 Isuzu Impulse. Are tires like Toyo Tires' Extensa HP suitable for this type of vehicle?

[Piazza_man]

Depends if you are planning on upgrading or already have 17 inch or 20 inch rims. But regardless of this you’ll still run into a slight problem with your speedo calibration as the extensa HP’s lowest profile on offer 225/45 R17 will have an overall diameter of 635mm. The Piazza standard diameter range should be 589.6mm, white the Irmscher and the ‘87 RS spec Impulse have a tyre diameter of 601.6mm. So in other words anywhere within that range will be fine if you want your speedometer to maintain its accuracy. I’m afraid 635mm will have a significant effect on your speedo calibration.