Changed alloy wheel now got bad acceleration and poor braking


#1

I changed my regular 13" wheel set to an 17" low profile alloy wheel set. I know the wheel base doesn’t really match. Handling is pretty good. But now I got bad acceleration and very poor braking. I don’t care about the acceleration but I’m worried about braking. When I apply brake the pedal goes down but still feels like wheels are dragging so hard. There’s no problem when I changed back to my old ones. Should I go back to my old wheels?? Does this means it’s also affecting my fuel consumption?
Old one - 13" alloy tyre 165/60/13
New one - 17" alloy tyre 215/35/17
Sorry for my bad english.


#2

I strongly suggest you go back to the original wheels and tires. Nothing in your drive train, suspension or brakes is built to operate with that much larger diameter tire and the cars ECM is clueless what’s going on. The computer may calculate that you are towing a U-Haul trailer up a hill all the time. Just wait till you calculate your gas mileage.You’ll rush to get back to the 13" wheels.


#3

The new tires and rims are almost 3" taller then the older setup. That’s a significant difference that will effect acceleration.

The new tires are also significantly wider which will cause more rolling resistance.

Change them back.


#4

This doesn’t answer your question, but I’m shocked that tires that much wider and taller fit without rubbing.


#5

Yes, you should switch back. 17" wheels are going to have vastly more inertia to overcome than 13" wheels. There’s more material than the smaller wheels, and more of the material is farther out on the torque arm due to the size.

And yes, it is hurting your fuel consumption.


#6

All good posts. The tire diameter of the 17’s is a full 10% greater than your original 13 inch tires. More like 54mm taller than 75mm but that is like taking 10% of the engine’s torque away from your engine and adding roughly 20% to the rotational weight your brakes need to control on top of the car itself.

You’ve proven it to yourself by going back to the 13’s and bringing back the performance. Sell the 17’s


#7

Good reply! I have a 21 speed bike and with some of the higher gears I have trouble pushing the pedals. A slightly larger tire on the 13 inch rims would have been a good idea!


#8

even a 16" rim results in darn smaller tire sidewall to work.


#9

YES!!

Very likely. But since your new rolling circumference is so much different that that to which the speedometer and odometer were calibrated, you have no way of knowing how much. You could estimate by doing some simple calculations, but since the rolling resistance is so much greater, and since the rotating mass is so much farther away from the axis (meaning it’ll take more energy to get the wheel moving), there’s no point in doing the diametric calculations. But I’ll bet the change affecting your mileage a bunch.


#10

Your acceleration loss is due to effectively running a 10% overdrive all the time. You are constantly 10% lower on the power band. Also the tire is wider and has more drag. Your fuel economy may not suffer as much as you think.

If you do the standard miles since last fill up/gallons required to fill the tank, your calculated mileage will measure lower, but it may not be lower if you add the 10% additional miles lost due to the increased tire circumference. It may even improve slightly, but with the extra width of your tires, I wouldn’t count on it.

Braking is a different issue. Your braking may only FEEL degraded. We had a discussion recently here where someone asked about upgrading to high performance pad and slotted and drilled rotors. I pointed out that the brakes would overwhelm his tires, making the vehicle prone to wheel lock or skidding. I was in the minority, but thats not important here. In your case the wheels and tires are overwhelming your brakes.

Your brakes are probably stopping the car just as fast as before, maybe even a tiny bit shorter. But because the wheels are generating more reverse torque (aka grip), the feel is like poorer brakes. Now if you were to upgrade to higher performance brakes with the 17" wheels, you would benefit. Better brakes would take advantage of the extra grip. Its all a system, the brakes and tires need to be in balance, matched to each other in performance.

Now all you need is an upgrade for the engine, maybe a turbo, to get back that lost acceleration. And maybe upgraded struts and swaybars to take advantage of the handling potential of the new tires.


#11

The only way you can calculate your mileage accurately is on a trio with known distance or over roads with mile markers. Some GPS units may do it also. I can’t think of any car sold in the US that came with 13" wheels that would have the power or brakes to handle 17"s. I a;so would not want to pud that much increase of a load on the wheel bearings designed for 13s.

In case my opinion was not clear, this was a really bad idea.


#12

@Mustangman
@oldtimer_11
@shadowfax
@Rod_Knox
@keith
@the_same_mountainbike
@MikeInNH
@lion9car
@Docnick
@Cavell
Hey thanks for all your replies. Everyone is surprised (even my self) that 17" could fit in. There’s no issue there so far. As you all are saying there’s a 10% power decrease.

  1. Is it not good for the engine or drive train or something? Or it’s just lack of acceleration??
  2. I got 1.8 gasoline engine and I’m thinking about upgrading to a 2.2l diesel turbo engine with all different axles and etc. If I do that can I use 17" wheel set???
  3. Does overwhelming brake means, it’s not good for the brake line pressure or it can result a fast worn out brake pads or something??

Note -17" wheel set is a sport version and it really is. :smile: Corners are so easy. As you can see I would really really love to keep this 17"


#13

Dylan, you really are going about this all wrong. First you have a post about a replacement engine not getting good fuel mileage and possible engine damage because you let oil level get too low. You have spent money on tires and wheels that are not really suitable for your vehicle. Now you want to put another engine in this thing. Seriously, stop wasting your money and find a vehicle with the features and looks that you want.


#14

@VOLVO_V70
Hey thanks for your reply. It’s not the same one. This one I’m talking about, I got it like a year ago for cheap price. Fuel consumption post is about another one, well I’m using that one for 7 years now.


#15

Overwhelming the wheels. When you apply the brakes, friction between the pads and the rotors cause a drag on the wheels. Friction between the tires and the road then cause the vehicle to slow down. The friction between the tires and the road is a torque vector.

With smaller tires and a smaller contact patch and other factors, your brakes could stop the wheels from turning completely aka lock-up. With the higher grip tires, your brakes may or may not be able to lock up the wheels. The torque vector created by the tires grip may be greater than the grip of the brakes. So you press as hard as you can, the car stops quickly enough, but you feel like the brakes just weren’t strong enough and the truth is, they weren’t.

The overwhelming is just a feeling, it doesn’t mean that the car is taking longer to stop. You feel like it should do more, but you will need to upgrade your brakes to get the most out of your tires.

You state in your title that you have poor braking, the reality is your braking is probably just as good but it FEELS like it isn’t. It’s a perception.


#16

what type of car is this? gotta be a small car with 165/60/13 tires. what is the look you are going for? i somehow see a jap heap with tires with 20deg deg camber. this would be a great time for a before/after pic of car. you do have an iphone?


#17

You increased the diameter by 2 inches(about 60mm). That’s a very large change, it also effectively changes your axle ratio. Your engine has less mechanical advantage now, so performance suffers. The smaller and less powerful the engine (and I’m guessing it’s pretty weak by North American standards given the small OEM tire size) the more dramatic this effect will be.

Your new wheels are also heavier than your old ones, which means you have more unsprung weight which will noticeably hurt braking and all-around performance.

What kind of vehicle do you have?


#18

I’ve seen them at some local car shows. There’s a lot of engineering in them. I would never do it or buy one, but I can appreciate the engineering and work that went into it.


#19

For the kind of money you are going to sink into swapping the engine, axles, and brakes to make your car capable of handling 17 inch wheels without wheezing, you could just buy a car that comes with 17 inch wheels.


#20

I could not tell that Dylan ( young person with big ideas ) had two different vehicles at first. But both seem to have problems . Not sure where he is located but I do think the person needs a reality check.