New Tires are Smaller Diameter

[zarstick]

Hello, Does anyone know if a transmission cog with more teeth will compensate for tires that are smaller in diameter then the original 195/70 - 14 ? Or should I try a cog with less teeth ?

 

[SKiddell]

Which "transmission cog" are you refering to ????

 

[Russ]

Is the speedo electronic?? I haven't looked but I doubt it. If it were (or if you converted it) you could adjust it easily with an electrical box of tricks.

 

[SKiddell]

Ahhh, by "transmission cog" you must mean the replacable take off drive for the speedometer cable thats tucked away on the RHS of the gearbox......when you said "transmission cog" you had me thinking you were going to start swapping out gears etc

 

[Mr.F]

Speedo drive gears are available in 16, 17, 18, 19, 20 and 21 teeth versions relating (usually) to rear differential gear ratios of 3.3, 3.5, 3.7, 3.9, 4.1 and 4.3 respectively.
A UK 240Z, for example, would come with a 19 tooth version matched to a 3.9 differential ratio. With smaller profile tyres you are effectively lowering the gearing (raising the ratio numerically), so a 20 tooth gear may be enough to compensate.

You may find that you need to change the sleeve that holds the gear in place - there are two types according to the offset required to accommodate larger or smaller diameter cogs...