Tire size on 2004 2.3l

[Mullacc]

just got a 2004 mazda b2300 Manual extracab. I believe 3.73 axle ratio. The tires look a bit undersized in my opinion. It is going to need new set of tires soon anyways so i was wondering if going from the stock 225/70/r15 to 225/75/r15 would be fine. (total diameter increase from 27.4in to 28.3in) Looking at Kumho Solus TA11 which has both sizes the 225/75 actually weighs slightly less.

 

[Blmpkn]

Up to a 30x9.5 will fit on stock wheels with no lift and no rubbing. It's what's on my truck, however, I re-geared the axle (3.73-->4.11) before I put them on to retain the factory final ratio.

Before the 30s I was running a 235/75/15 which is essentially a 29x9.25 and I was more than happy with how they looked and rode. I'd suggest going with them, over the 225s.

 

[Dirtman]

I run 235/75/15s (very cheap and common size) on my 09 2.3 with 4.10s. (Factory size was 225/70/15). They fit well and look nice.

 

[Mullacc]

ok. Checked my door jam tag and the Axle code is 87, which accord to this site is Open 7.5" 4.10.

So 235/75/r15 should be fine? Can i just pop them on or do i need to adjust something so the Speedometer/odometer are correct.

 

[Dirtman]

Your speedo will be off slightly. You cant just change a gear in a 2004, its all computer controlled. I THINK you can fix this with forscan (free laptop software) but not 100% sure. With the bigger tires your speedometer will read slower than you are actually going. Unless you really push the speed limits though it won't be much. At 65 you will probably be doing 72? Someone can do the math... driving reasonably no one will notice (police).

 

[pjtoledo]

check your current setup with GPS. you will probably find it reading high. (edited from low)
I found my speed-o was more accurate with slightly larger tires.
235/75-15 worked good on my 2005. currently it has 225/70-16 which works great as a daily driver with 3.73 gears.
your 4.10 gears will be happy with 29-30 inch tires. your brakes, not so much.

 

[Blmpkn]

With factory tire size the speedo will say your going 4mph faster than you actually are. It will read 2mph faster than your actually going with the 235/75s. 30" tires read dead nuts.

I've read its because ford used the same related parts between the 4x4s (which come with 30" tires) and the 2wds (which came with 27.5.)