Hi I have a 1986 ford ranger 2wd 2.9 v6. It had 14 inch wheels factory but I switched to 15 inch bullet hole wheels. I was just wondering how much it would affect the speed overall.

 

Depends on the tires.
If you get the right ones (i.e. Lower profile) there won't be any difference.

 

If bigger will have effect on overal gear ratio. I run 235-65 15 on my 94 with 4.0. speedo off bout 2-3 mph, odometer off 4miles /100 driven. originally had some 14 size unkown, son had put 17inch low profiles on it and I thought it looked like crap thus the change to 15's when I got possesion of truck.

 

I had an '86 with the 2.9 and a 5 speed. I went from the stock 205-75x14s to 225-75x15s. If you think it's slow stock, try that combo. Turned it into a real pooch. It had 3.45 gears, and could have used 4.10s with that tire.

IF your new wheels are lighter and the tires are about the same diameter, you will not notice much. But if the tires are larger in diameter, you will notice it quick and your acceleration will be noticably slower.

 

You have to remember the speedo is electronic-no more cable-the pcm is set up from the factory, with that size wheel programmed in it. It can be reprogrammed at the dealer for a price. Anyway, I went from 225-70-15 to 235-75-15(taller tire), and used one of those online tire size calculators, and it said my speedo would be off about 2 mph at 60 mph. Not that bad, but the puter was programmed for a 15. Going from 14 to 15 is going to noticeably throw off the speedo. My gas mileage dropped a few miles per gallon with these meats on, but still does well-2.5L w/5-speed manual, so I control shift points. My next set I'm going to put on 205-75-15, and see if the ride and the mileage is affected. I like the 75 series for the taller sidewall. Never did like all that 17 to 21 inch stuff, not enough sidewall, and you gotta worry about denting your rims going over potholes and going into gas stations. Some guys can't even turn like they should, all for show!

 

Not all but most 14 inch Rangers used the 3.45 gears. when Ford put the Ranger on 15 inch rubber the most common gear used was the 3.73 and they did that so they could get enough power for the truck to pull itself down the road. If you go to a tire calculator that asks for rear gear ratio along with tire size you will find that the revolutions per mile are basically the same from a 215/70/14 3.45 gear set to a 225/70/15 3.73 gear set. My 03 Ranger with a 2.3 dohc 4 cyl is a dog on 3.73 gears but gets 28 mpg over all. I am seriously contemplating swapping in a 4.10 rear to just get a little better pulling ability.

 

Its an 86 so it is cable driven! Also my 94 has a drive gear that you can change but it made no difference when I did, it did not correct enough. I went back to the stock setting and its close enough, the odometer is what is off now 4 miles per 100 driven. Speedo accurate up to 55!