Spare Tire Size

[P1W]

I currently run Toyo Open Country MTs which are 295/70 r17. I’m looking at the same make and model but at a slightly different size of 285/75 r17. These new tires have a diameter that is approximately a half inch larger than my current tires. I’d like to save money and buy only four tires. My question is whether this half inch difference will hurt my gears if I need to run the old spare.

 

[Fishtaco]

I currently run Toyo Open Country MTs which are 295/70 r17. I’m looking at the same make and model but at a slightly different size of 285/75 r17. These new tires have a diameter that is approximately a half inch larger than my current tires. I’d like to save money and buy only four tires. My question is whether this half inch difference will hurt my gears if I need to run the old spare.

Just leave your original spare for show or ditch it! Tire repair kits, cheap as chips inflation compressors tire slime and tire repair aerosols along with roadside assist makes spares just about redundant these days unless you are considering possibly ripping your sidewall beyond repair or going somewhere really remote?
I have not change a flat to spare in over 30 years other than on a heavy vehicle.

The aussie way! skip to 8.30

 

[Mr. Bills]

I currently run Toyo Open Country MTs which are 295/70 r17. I’m looking at the same make and model but at a slightly different size of 285/75 r17. These new tires have a diameter that is approximately a half inch larger than my current tires. I’d like to save money and buy only four tires. My question is whether this half inch difference will hurt my gears if I need to run the old spare.

Short answer: No, it won't.