Anyone considering upgrading from the OEM Bridgestone Turanza EL400s on the EX, EX-L models? Possibly switching to a 205/50/16 from the original 185/55/16. The Bridgestones do not have great reviews on tirerack.com.

 

I have a set of 205/50ZR-16 Continental ExtremeContact DWS tires coming today. Aftermarket 16x7 wheels coming later this week. Will report once they're installed.

es

 

I wouldn't put much stock in Tire Rack reviews. Unless they are based on instrumented tests, reviews don't mean much. Most of them are from fanboys who just spent $1000 on tires, are they going to say anything bad?

Are the OEM Bridgestones causing you some issue? If not, run 'em and be happy.

 

What are the advantages of changing size? I know nothing whatsoever about how sizes affect performance and ride and such. Does changing size have any adverse side effects such as altering the accuracy of the speedometer or anything else?

 

There are advantages and disadvantages, and you have to decide what is most important to you.

I chose the 205/50R16 size because it is virtually the same circumference as the OEM tire, which means my speedo will continue to read accurately, but is wider (by 20mm) and with my aftermarket wheels, should provide better handling (it could also mean easier hydroplaning!). The primary reason, though is to enhance the looks of the car.

The challenge with going wider and changing offset is that you can run into interference problems either with inboard suspension components, or the fenders. I may run into this problem with my front wheels/tires, and really won't know until I install them. Hard data from folks with aftermarket wheels and tires on the GK seems to be hard to find right now.

You can look at other combinations of wheel width/diameter/offset and tire widths, and come up with quite a few variations, some of which will work fine, some of which won't without other mods to the car. Some combinations will affect your speedo reading by several MPH.

If you're into hypermiling, look for the lightest weight wheels and tires - as tires weigh less than wheels in most cases, going to a *smaller* size (15") may actually result in a lighter combination.

Forged wheels are stronger than cast (OEM wheels are typically pressure cast), but are also much more expensive. If you're planning to race or generally hoon your car, forged may be worth it. Cast is probably fine for street or DD use, since that's what your car came with.

This link goes to an interactive wheel/tire calculator that offers suggestions on what is likely to work or not (note that it is *not* specific to the GK Fit, so only take it as a suggestion).

HTH,

es

 

You're assuming that the speedometer is accurate to begin with! Most speedometers read about 3-4% high as delivered from the factory. These days, it is easy to figure this out if you compare the reading to a GPS.

On my Scion, I went from 185/60R15s to 195/65R15s. I wanted a bit more ground clearance and a taller final drive ratio. My speedometer is now perfectly accurate, but my odometer reads about 8% low.

Some people think that a wider tire will improve their cornering ability since this is the common wisdom spread by the motoring press. This only applies if your driving style is so aggressive that you are heating the tire to the point where the rubber is too hot to maintain traction. If you are doing this, you are very likely to be a member of that motoring press who doesn't pay for their own tires. Wider tires spread the heat over a larger area which is why they are used on racing cars.

Other than that, they are just for looks.

 

Good point on the low-from-the-factory speedo reading. I've passed a couple of those "WARNING YOUR SPEED IS __" rigs with the Fit, and so far it's been dead on each time. I'll have to check it with my GPS, too.

As for wider track (courtesy wider wheels) = better handling, physics is on your side there, as you are widening the base of a triangle that goes from each wheel contact patch center to the center of gravity / center of roll. You're correct that you won't really notice it until you're pushing the car hard, but it *does* make a difference. As for the tire width, there are a number of factors that come into play; some have to do with the construction of the tire itself (sidewall stiffness, for example), some with the suspension on the car.

es

 

just for info for you guys, the wells of the 2015 have a lot of room. these are Kosei K1-TS 15 x 7 with a 38mm offset, and Hankook RS-3's in 225-45-15. they had plenty of room.



i did jack the lower control arms up in the corners to simulate a 2.5 inch suspension drop, and they still had the clearance to turn the front wheels lock to lock, and will have room for suspension travel when the car hits bumps. i would say that is you are crazy enough, you could fit a 245mm section width tire, and it will have clearance. they really do have big fender wells. but IMHO, a 205mm seems to be the perfect width for these cars.

i dont think a 16 inch wheel will have any problems fitting with the same offset either, assuming you keep the tire profile around the same diameter as stock.

no, these are not the wheels i am going to put on the car... these are from my 1989 Civic Si SCCA STC autocross car. you can read about why i put the wheels on the Fit in the newbies section.

 

Thanks for posting the pic, Daveds50. I put your wheel/tire specs in the online calculator, and yours are 1.1" shorter in diameter than the 205/50R16s I'll be using (which have virtually the same diameter as stock). My wheels are 16x7 +40 and should sit very similarly to how yours look. I'll post pics once the wheels get here and I get them mounted and installed.

es

 

Thank you for taking the time to explain. This was incredibly informative. I feel as if I have a better understanding now.

 

Same here on both methods of testing. Mine is also dead on -- the first car I've had that isn't showing 5-10% faster than I'm actually going.

 

I'd expect that those rigs would read a bit high as well, to shield the manufacturer from liability and encourage people to slow down.

I've checked a lot of speedos, dating back to the day when you needed a stopwatch and the specially marked "speedometer check" sections of highway to do it. The only stock speedo I've had that was dead on was on a BMW R100RT motorcycle.

Here's a good speedo calibration:

 

just a note, don't trust the tire calculators. they assume that the tire measures exactly what the manufacturer claims. which, is rarely the case.

example: back in the day when the Falken Azenis RT-615 was the hot autocross tire in Street Touring classes, i bought a set of 205-50-15's. stuck them on a set of 7 inch wide wheels, and put them on the car. was wondering why i had so little clearance. took the wheel/tire, and measured it. 221mm wide section width, and was taller... but was true to the 50% of the 221mm width.

that has been the case since. almost all the hot tires i have used, including the RS-3's, have been oversized. if you ever saw a 225-50-13 Hoosier A6, you would wonder if it was designed as a 13 inch tire for a Corvette...

best to go to the manufacturers websites. most of the reputable tire companies give the exact actual specs of the tire. something that none of the calculators can do.

 

Interesting… I just checked the Continental site (for the 205/50R16 Continental ExtremeContact DWS tires I purchased), and the overall diameter listed there matches the tire/wheel size calculator I linked (24.1"). The overall section width listed on the Continental site, however, is wider (213.4mm) than the 205mm listed on the calculator.

I received the tires yesterday, and prophetically thought to measure them – the actual width is indeed 205mm. Actual tread width is a bit under that.

YMMV, of course.

es

 

exactly. different manufacturers, different models, different results.

you dont have to worry about if they will fit though, these cars have huge wheel wells.

i think you made a good choice in tires. the Conti DWS is one of the best rain tires around. fairly good dry traction, but excellent in the wet. a lot of us racers that have to use street tires keep a set just in case. i would run them on the street if i didn't have so many sets of tires already laying around.

 

Hopefully not for many, many miles. My tires are new and I want to wear down all the rubber I can before I spend more money to replace them. If I was going to spend money now, it would be for winter tires, but I don't even need those in Tennessee.

Having said that, I am one to replace tires when they start to wear down. It has been my experience with my previous 2008 Fit, the tires would seem fine for quite a while, but when they started to go, they would go quickly. I alway's knew it was time to buy new tires when my old Fit started to "growl" on the Interstate.

 

Quick pic of my EX with 16x7 +40 wheels and 205/50R16 tires installed:



es