Wheel and Tire Size

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imported_TheFiveO1

New member
I'll be the first to admit that I do not know much when it comes to tires and wheels so I pose this question to whoever has information to share.



I have an 06' Corolla that has the standard 15" tires. Will upsizing to a 16" or 17" tire/wheel combos have much effect on the gas mileage and or the amount of load placed on the engine? I don't want to overload the tiny 1.8L engine.



Thank you in advance for your input:thx
 
TheFiveO said:
I'll be the first to admit that I do not know much when it comes to tires and wheels so I pose this question to whoever has information to share.



I have an 06' Corolla that has the standard 15" tires. Will upsizing to a 16" or 17" tire/wheel combos have much effect on the gas mileage and or the amount of load placed on the engine? I don't want to overload the tiny 1.8L engine.



Thank you in advance for your input:thx
Click to expand...



If the tire diameter stays the same (bigger wheels with lower profile tires), the only factor that should affect performance is the weight of the new tire/wheel combination. (Not taking any increase in tire width into consideration.)



If you change the tire diameter, you will effectively change the overall gearing of the car. Bigger diameters have the effect of raising the gearing and slowing acceleration. Smaller diameters = lower gearing = faster acceleration = higher engine rpm at any given speed = higher fuel consumption.



Increasing the weight of the tire/wheel combination can have a significant effect on acceleration, braking and handling. You'll have more unsprung weight to deal with (the worst kind), plus it will be rotating. (I know a Ford dealer who received a letter from Ford Motor Company advising warranties could be voided on trucks with dealer installed big wheels and tires.)



Lower profile tires came from the race track. Advantages include better turn in and steering feel. As the road wheels turn into a corner, tire sidewalls flex and then the tire tread changes direction. Taller tires have more rubber between the road wheel and road, thus more flex in the side wall. Lower profile tires have shorter side walls thus less rubber to flex as the car changes direction.



On the street, lower profile tires ride rougher and are more suseptable to damage from potholes. Less rubber between the road wheel and street = damaged sidewalls and bent wheels.



If you choose bigger wheels, make sure you keep the tire diameter the same as stock. you should also select lightweight wheels. Tirerack.com lists wheel and tire weights. Make sure your new wheels/tire weights are close to stock or lighter. (Yes, that means weighing one of your stock tires/wheels.)



You also have to be careful in selecting the proper wheel offset (also known as backspacing.)
 
Holy cow STG.. THANK YOU !! I feel like I just completed Auto 101!. Do you come from a racing or engineering background?

After reading your reply, I think I may just go with "better" stock size tires and get some nicer wheels.

Thanks again:wow:
 
It'll have small effect on gas mileage, because they'll be adding weight. I'm not sure about the load question, but tons of young guys over here like to add big wheels and low-profile tires to their kei-cars and subcompacts, seemingly with no problems.



You'll also probably be getting a pretty harsh ride. I replaced the orig. 15" wheels on my '92 Nissan Silvia with 16"ers, and even with a fully independent and relatively compliant suspension, the ride quality really went downhill. I'd at least stay away from the 17" wheels if I were you. Lots of folks I know (on various types of cars) end up going back to the original size because they can't stand the bumps and bounces anymore.
 
TheFiveO said:
Holy cow STG.. THANK YOU !! I feel like I just completed Auto 101!. Do you come from a racing or engineering background?

After reading your reply, I think I may just go with "better" stock size tires and get some nicer wheels.

Thanks again:wow:
Click to expand...



A lighter stock size wheel with a better tire would be a good choice. I found some surprisingly light wheels for my 2005 Subaru Legacy GT (for snow tires). The brand is ASA. They are inexpensive, look good and are made under license from BBS in Germany. My stock sized close outs cost $119 each and are as light as the same sized BBS wheel (over $400.)



15" X 7' ASA $99 18 lbs.



asa_js5_ci3_l.jpg
 
I like the look of that rim and will see if they make them for the Corolla. I realize I have a little commuter car, but I wanna make it look nice. It is the Metallic Charcoal grey color and with the tinted windows it looks fairly classy. Just needs wheels to complete the look. At first I was thinking of going with gunmetal grey wheels to match the paint, but I like the muted anodized aluminum look of the rims you posted here. If I keep the car looking decent, should be a nice pass along for my daughter when she turns 16. (OMG I am getting old)
 
I pulled that picture from Tirerack.com after searching for 2006 Corolla wheels. It has the correct 38mm offset.
 
If you don't know how to do it by hand, here's a good calculator for figuring diameter and speed differences. You can play with tire sizes in the second table to find one on a +1/+2 rim that will keep your rotational distance as close as possible.



Tire size calculator
 
I went from 15's to 17's. My original tires were 195/60-15 and I went up to 215/45-17. The ride isn't harsh to me. At most I would say it's just slightly more harsh than stock. Usually on the forums the ones that were complaining about ride harshness were the ones who bought a package deal and got undersized tires such as 205/40.



According to TireRack, your original tires are 195/65-15 and if you were to go up to 17's, you'd be riding on 205/50-17. I think there's still plenty of tire on there to absorb shock. Your ride quality shouldn't be too bad. Join a Corolla forum and see what other members have to say. You might even be able to fit some wider tires on there, maybe 215 or 225 mm width, but that will definitely change your speedometer/odometer.



Lightweight wheels are nice but you have to take everything in consideration. For me, I'm the type of person that hates skimping out the first time and having to buy the same type of product again because I was too cheap in the first place. When I originally was upgrading my wheels, my budget was between $800-$1200. But in my mind if I were to spend up to $1500 for lightweight cast wheels, I might as well go for the real deal and get forged wheels from a reputable manufacturer. 14 lbs sounds great and lightweight, but it made me question the structural integrity of the wheels. I would be more prone to bending a rim if I were to hit a pothole. In the end I ponied the extra dough for some Volk Racing wheels from Rays.



Don't expect a completely different beast in terms of acceleration/deceleration/braking if all you'll be doing is daily driving. You should be ok with most aluminum wheels. Just stay away from the ghetto chrome bling bling crap (unless you're Australian). That's when it starts to become way too heavy.
 
BlackElantraGT said:
You might even be able to fit some wider tires on there, maybe 215 or 225 mm width, but that will definitely change your speedometer/odometer.
Click to expand...



At 225mm a 45 series tire would be an exact match.
 
I went from 15" to 17" wheels and tires on my Scion xB and didn't notice much change in ride quality. I recently upgraded the tires on the car and the ride got much better and quieter. I haven't had any issues with damaged wheels from the short side walls, but in Georgia, the roads are pretty good.
 
I think what you really need to remember when upgrading tires, though, is your braking. You know all the bling donks on the road with 22's? Yea, they have enough trouble accelerating, and when they need to stop? lol, forget about it.



A 2" upgrade won't kill your braking ability, but you should keep in mind it will be affected. I'm glad you aren't considering more than 2" because I personally consider anything more than 2" to be excessive (over stock, unless your stock was steelies)



Also, you may want to make sure you won't have any rubbing problems when you turn and/or go over bumps, potholes, etc.



Also, your speedometer and odometer readings will be off... not by much, but you should still keep that in mind. You'll be going faster and farther than your instruments will be telling you... keep that in mind to avoid tickets!
 
Yeah, definitely don't go more than 2" from stock unless you had some 14" steelies like paul34 mentioned.



I think the 17's are nice upgrade because most people who get rims are doing it more for looks than performance, and since you're going to be spending a pretty penny, 17 inch seems like a better deal plus has better looks.



I would suggest getting tires that are slightly oversized vs undersized because if it's undersized, your odometer is going to show more miles on there than you actually traveled, whereas with oversized it's the other way around.



My diameter is 1.7% larger than stock, but it hasn't really made much of a difference throwing my speed off. It is still close enough. You really won't notice any effects on the load on the engine or gas mileage. Any effects are minimal at most, unless your new wheel/tire combo weighs significantly more than stock.
 
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