[theunchosen]

Originally Posted by theunchosen

1.) go for the bigger tire and wheel. It will increase your final drive ratio. So you car will claim its going slower than it actually is. So at 3000 rpm you will be going slightly faster than you would with the 14 inch tires.

2.) safer

3.) the higher pressure will allow better FE due to less rolling resistance and it will be more constant and not risk blowing a tire because it gets low(safety again) but also if it has constant pressure its more RR and FE frinedly

Originally Posted by almightybmw

If the tire fits, wear it. I've never liked running on old mis-matched tires, just doesn't sit well with me in the safety department. Ditch the mixed 14" tires, but keep the rims. Run the 15" set until you find a better more suitable 14" set of tires. I'm assuming the fiero has wider tires than your neon, so that'll hurt, but the taller tire may offset to put you back where you started.

to address the air pressure statement, the sidewall max is rated at the tire's weight max, something I doubt most people run within 70% of. Do contact patch tests first however, before jacking the pressure above and beyond. All vehicles are different, the blanket statement of "pump those to 50psi" doesn't fit.


Safety. New tires are the reason you should change, regardless if they drop your mileage by 1-2. Safety of you, your passengers, and others on the road. Never sacrifice safety for better mileage.

My max tire weight is actually pretty close its rated for a total of 4000 lbs(car is 2050 plus me(2190)) and after a dip in the road at 60-70 its going to get very close to being at max loading for an instant but its not static loading either. Impact loading is much more stressful than static. The max load weight will also have a safety factor incorporated but it won't be a very large one because not many 14 inch wheel vehicles weigh over 3Kips.