Pros and Cons of having bigger rims..?

Question

I own a Mazda Astina with 13" stock rims. I'm planning to change to 15" or 16" rims. What are the pros and cons of having bigger rims.. Will there be less torque?

Are there any advantages other than the look? So why do people change to bigger rims?

Answer 1

Changing from 13" to 15" or 16" rims is not the critical factor in torque. You have to look at the entire size of the rim and tire assembly together. If you change from 13" to 15" rims, install a tire with a smaller height, and wind up with the same overall height of tire and wheel, you haven't changed any ratios relative to torque delivery to the ground.

In other words, if you have a 13" rim and a tire that adds 4" to top and bottom, and you change to a 15" rim and use a tire that adds 3" to top and bottom, you have the same height wheel each time - 21". The height of the tire determines it's perimeter, and if it's the same with both options, you'll find no change in torque or speedometer accuracy.

If you do wind up with a "taller" tire when you finish (meaning it's perimeter is farther around), then you will be changing your final gearing ratio. In other words, a taller tire will turn less revolutions at the same ground speed for a certain distance, therefore your engine will be turning less revolutions at the same ground speed.

I have used larger tire sizes (taller) to decrease engine RPM at the same ground speed, and consequently use less gas and make the engine last longer.

Given the same engine rpm in the same gear, a taller tire will get you farther down the road, the shorter tire will take you less distance, because it's perimeter (which determines how much ground it covers) is less.

If you want to get higher rpm for the same speed, make the tire shorter. If you want to get lower rpm for for the same speed, make the tire taller.

So, the roundabout answer is this..
Taller tires with the same gear ratios will cause you to get out of the hole slower because you will be faster when reaching a certain rpm. Smaller tires with the same gear ratios will cause you to get out of the hole faster initially, but you'd better be able to shift faster or you'll lose the advantage.

Answer 2

The only factor is cosmetic. There is no enhancement coming from changing the size of the rims. Even if overall diameter remains the same there will be negative handling and suspension affects. Most likely the wheel offset will change, and with this the scrub radius. This will cause tire wear issues, which I see alot at my shop, and can affect the way a vehicle handles. Even the untrained people who say that a lower profile tire can enhance steering response (true in alot of cases), who says that this is a good thing? The engineers have designed your vehicle with a great number of factors in mind for safe handling, braking and steering responce, among other things, and making only one change to one system without knowing the affects (being an engineer with amazingly expensive equipment and training) can cause problems with the drive train, transmission, suspension components, etc. I recommend purchasing more appealing rims, of the same size, from the manufacturer or from someone that a dealer technician or parts specialist may recommend, and make sure that the offset stays OE, because this is the only way you will still be able to align the car as well as ensure that braking and handling remain safe and optimal. Anything other than OE rims are cosmetic only, there are absolutely no performance benefits in any way.

Answer 3

The 1st negative, as you probably already know, is cost! Secondly, if the tires profile (the distance between the edge of the rim and the tire tread) is very "low", meaning small, it is very easy to damage a rim from a pothole or dip. The tire can be damaged more easily also. Thirdly, it can possibly negatively effect performance! Bigger is better? Not always. If the overall outside diameter of the new tire size is greater than your stock tires you will have a decrease in acceleration performance unless you compensate by going to a higher (numerically higher) differential gear ratio. Also just the weight of the larger rims and tires will decrease acceleration performance unless they are lighter than your stock rims. On the plus side they can give the car a hotter look. They can increase cornering capability. And if the overall outside diameter of the tire is smaller than your stock tire, it can actually slightly increase acceleration performance.

Answer 4

There are a number of issues to consider when going to a larger tire. The added diameter can cause wheels to rub on the fenders or wheel wells. The larger wheels tend to be much heavier and change the handling and feel of the car. The larger wheels will also affect the speedometer reading because they will rotate at a different RPM. Also wheel offset must be considered. Offset is how offset the wheel is with respect to the hub. Too much or too little offset can cause rubbing of wheels on body, brakes or other parts. Find a bulletin board or chat site for your car and find what others have done. Tirerack.com has offset and radius for your car. Never heard of an Astina but I had a Miata and the larger tires really sucked.

Answer 5

the torque is produced by the engine not the tires. the bigger the rim the less sidewall you have to fit in the tirewell. At the local tireshop the manager told me that most people buying the big rims come back with bent rims after they have hit a pothole or two, because there is no "give" in the tire like the regular (13inch)tires have.

Answer 6

It depends on the location of the rotating mass....

There are wheels that don't displace too much mass on the outer circumference of the wheel....offering no added rotational friction. At this point it leaves the effects to the tires you add.....

15" wheels with 195/50s are good....
16" with 205/45's are also good....

If you go 17's all bets are off and you will lose lots of torque

Answer 7

I think you should get 18'' to 19'' rims for it. It would increase steering performance and traction after getting them you should go to a dyno to check on torque Questions.

Answer 8

if its at the stock height, then there should be no problem. BUt if its lower about 2inches or more then you may have rubbing on the fender walls.

Answer 9

You can add more weight to your car when you upgrade. It depends what kind you buy. motegi, rota, volk, 5zigen,enkei,kongi: all light wheels