Going from 12" to 13" and I have a question"

[bullet101]

First I'll say that I'm a Mazda technician so I have access to any Mazda factory parts that may be applicable (which is a lot)

So I bought a 93 festiva in the summer and its time to get some winters, I've already decided on wheels and tire size (155/80/13) and I know its going to throw my gauge out but I want to fix it. What speedo gears do I need to get accurate (or more accurate)? I know there are vehicles that have MTX 5's with 13 inch tires, however I don't really feel like pulling trannies and ripping them apart randomly. If anyone has done this before it'd be a great help.

[FestYboy]

you could run an aspire speedo, OR don't worry about it because the differance is not even 2mph @ 60.

[Advancedynamix]

^ like FestYboy said, the inaccuracy will be so minimal that it wont even be noticeable on an 85mph speedo. When your speedo is maxed you'll be doing 88 rather than 85. Still more accurate than the majority of vehicles sold in this country in the last 40 years.

[Safety Guy]

I use GPS for trips and simple math for better accuracy when figuring mpgs.

An Aspire gear would help a bit I suppose, but would still only correct for 165/70-13s. They aren't going to be all that accurate to begin with though, so why do all the work?

Karl

[TheresGabe]

On my 155 65 13's my speedo is dead on with my GPS.