Tires questions

[Quynty]

I have 16" inch wheels on my SV with 205-45-16 tires. I just ordered some lightweight apollo 13 inch wheels from Caterham. Just wanted to see if they make the car more nimble. My only concern is that I live on a dirt road with a clearance problem--it scrapes a bit with the wheels I have. Does anybody know what size 13 inch tires I will need to get about the same height? I was thinking 185-60-13, but maybe that won't be high enough. The total diameter of the 16 inch wheel\tire combination is 22.5 inches. I do have an aluminum skid plate fitted on the bottom of the sump. The engine is a Zetec. Thanks to any one who can help.

[vstibbard]

Think you should aim this question to the Lotus 7 club site as you will find other owners of your model able to reply with their experience.

V

[1owner69Elan]

I have 16" inch wheels on my SV with 205-45-16 tires. I just ordered some lightweight apollo 13 inch wheels from Caterham. Just wanted to see if they make the car more nimble. My only concern is that I live on a dirt road with a clearance problem--it scrapes a bit with the wheels I have. Does anybody know what size 13 inch tires I will need to get about the same height? I was thinking 185-60-13, but maybe that won't be high enough. The total diameter of the 16 inch wheel\tire combination is 22.5 inches. I do have an aluminum skid plate fitted on the bottom of the sump. The engine is a Zetec. Thanks to any one who can help.

Use a tire calculator like: https://tiresize.com/calculator/

You can compare diameters (radii), as a good first approximation of height differences. It won't give you the amount of compression of the tires due to loading, and resultant lowering of the car, however.

Here what the calculator says for the two different sizes you specified. It indicates that the 13 inch tires will lower the car by ~0.8 inches.