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18" vs. 19" tires

19854 Views 21 Replies 13 Participants Last post by  RIT333
So it looks like my preferred color combination might be possibly be available but with the 19" chrome wheels instead of the 18" aluminum wheels (my preference). If the salesman can get a dealer swap, I'm gonna go test it out.

I've seen reviewers comment on the difference between the two tires, but I'm not convinced that writers of professional reviews are not necessarily coming from an unbiased place and/or aren't really in tune with what the average shopper values in the drive feel.

Any thoughts? I don't know how I feel about all that chrome (as the SLT-2, in my opinion, is just this side of having tastefully done chrome). One salesman told me that changing the wheel size would void the warranty. Another told me that it could be done without voiding the warranty? What say y'all?

On the plus side, the 19" wheels will fill up the wells nicely, but I'm concerned about road noise and ride roughness/firmness. Not to mention having larger tires (this coming from a guy who was also considering the VENZA which had a minimum wheel size of 19").
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I too would rather have the 18" wheels/tires. I do like the chrome but hate the harsh ride of the 19" tires. Every article I read on tires say the bigger the tire the harder riding the car is. I am paying for it now. At least I don't have those awful 1" sidewall tires that you see on the "cool" cars. ;D
You won't void any warranty by replacing wheels/tires, but you will need to re calibrate the computor for the different diameter.
The aluminum 17 wheel with the 225/65/17 is
Overall Diameter: 28.51 in -or- 724.15 mm
Sidewall Height: 5.75 in -or- 146.05 mm

I couldn't find the diameter for the 18 or 19 tire...but...I doubt they are "bigger" or more specifically have a larger diameter
I imagine the sidewall height on the 18 and 19 are shorter to keep final drive ratios the same/similar for all rim sizes to maintain mpg considerations (and probably tow rating as well)

On the 2LT...all 3 rim sizes are available depending on powertrain and required options to get the size you may want to have (see the build your own on the Chevy website)


So...if the outside diameters are indeed similar or the same as one would expect...
Then the wheel well would not be "filled out" any more no matter the rim size...
It then comes down to:
1. Your choice as far as appearance
2. How much ride stiffness you will feel from the smaller sidewall

The suspension on the NOX / Terrain (IMHO) is already stiff compared to other cars (yes I know this is a crossover...I'm just sayin') and you may feel uncomfortable with less sidewall on the larger diameter rim.

As far as warranty goes...so long as you run a rim/tire combo similar to what is put on by the factory (diameter/backspace/width/offset) you are covered. This would hold true even if you installed factory rims of a different size than what was put on at the factory (provided you stay within the powertrain and required options for that rim)


Also related to warranty coverage is the Magnuson–Moss Warranty Act
Here is a a link if you care to read a copy of the Act itself (I don't think Wikpedia is the end all / do all but they do have a copy of the Act posted)

http://en.wikipedia.org/wiki/Magnuson%E2%80%93Moss_Warranty_Act

Basically the Act prohibits the denial of warranty based on the simple installation of a Non-OEM part.
Without this protection we would be forced to use OEM oil filters as only one example.
SEMA...the aftermarkets product group would not exist today if it weren't for this act.
Trucks with legitimately installed lift kits would have no warranty protection
etc etc etc
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Eh....forgot to mention that the Magnuson–Moss Warranty Act

also provides that the Dealer and/or Manufacturer and required to PROVE that the "installed Non-OEM part/s" caused the failure of an otherwise covered part/s

As an example speaking of rims...

If one were to install a rim whose backspace was different from recommended...and the "shift of the center of mass" placed too much strain on wheel bearings and/or hubs...that could/would void warranty on those parts.

If the tire size exceeded the recommendation of the manufacturer and a transmission or final drive problem were to occur as a result... a warranty repair could/would be denied.

It all depends on what you do and how you do it.

Another example...

Chevy released a bulletin a couple years ago concerning after market air filters...the type which are considered "lifetime" and are routinely cleaned and "oiled" and reinstalled.
I'll use K & N just as an example here.

It was discovered that some folks were over oiling the filter after cleaning.
The excess oil was being sucked past the MAF (Mass Air Flow)...the ECM would get conflicting data and transmission shift data was being compromised...

In the cases where OVER OILING was present...transmission repairs were being declined. Dealers were required to show/prove that air filter oil contamination was present in the Mass Air Flow Sensor

BUT...the simple installation and use of a K & N filter in and of itself did NOT void the warranty.

So it is not just a matter of what is installed...but how it is used...
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Speaking of warranties, I did get one for the rims and tire from the dealer. Yes, it is a sucker bet, but I figured the first time I got nasty road rash or hit a big pothole and had to have a rim replaced, it would more than pay for itself. For the record, I went through a similar deal where I did not want the 19" rims and all the color/trim vehicles I liked had them so I kept passing on them. As an after thought, I do like the look of the 19" rims, but they are factory. I may look into 19 or 20" rims in the future, but not for a while.
This may be a silly question, but is it possible to get 19" tires with roughly the same sidewall height as a 17"?
NoobNox said:
This may be a silly question, but is it possible to get 19" tires with roughly the same sidewall height as a 17"?
It is possible, but it might not fit in the wheel-well, and it will throw off your speedometer and odometer because the overall diameter will be a lot larger. Don't do it !
NoobNox said:
This may be a silly question, but is it possible to get 19" tires with roughly the same sidewall height as a 17"?
Yeah...as mentioned above...you don't want to go there...

Another reason...even if it did fit...which it won't...you would easily exceed the max tire size recommended by Chevy for the Terrain/Nox and those "evil" warranty exclusion things I mentioned above WOULD be lurking in your corner just waiting to wreck havoc...

FWIW...I don't recall a 19 inch tire with a 5.75 sidewall height...I think 19's start at a tad over 6 inches in sidewall height which puts the diameter (depending on cross section) somewhere in the 31.XX neighborhood for diameter...

You might squeeze it in the wheel well sitting static...
But you're not gonna go over bumps without tearing up stuff...
and you're gonna be making 12 point turns...LOL
As far as speedo calibration goes...

A little known fact is Dealers are allowed to make ONE complimentary ECM speedo adjustment as long as it is done within the warranty period and the customers new tires are within the recommended size.

Also available for purchase (for $200-300+ US) are hand held tuners which plug into your OBDII port...it is a simple procedure to tell your ECM what new size tire you have and have the ECM calibrate for that tire.

Just plug into the port (under the lower dash valance to the left of the steering wheel)...
Remove the OnStar fuse (so data collection by OnStar is disabled during the upload)...
and follow the menu on the hand held...
Thanks all for the responses!

I asked the salesmen if the dealership could change the wheel/tire sizes. And one told me it would void the warranty and the other said he could do it if I really wanted it. To be fair, neither one sounded sure and were probably trying to get me to commit.
bigmaestro said:
I think this was posted elsewhere, just can't find it right now.
To sum up though, I've gone over this in detail with my dealer Tech and he checked with GM Tech Support to confirm as I run a smaller rim for winter (18's) so to compensate you can run a 245/60R18 tire so that your speedo isn't out.
You can reprogram for speedo and odometer but only if you are upsizing the wheel and tire with GM factory sizes. So if from factory you have 17's, you can upgrade to 18 or 19's with factory tire size. And if you have 18's you can upgrade to 19's with factory tire size. The GDS computer will not allow to downsize, ie. 19's to 18's or 18's to 17's. Keep in mind your axle ratio will stay the same so depending on your application you may want to consider this.
[/color]

MOCHANOX said:
The aluminum 17 wheel with the 225/65/17 is
Overall Diameter: 28.51 in -or- 724.15 mm
Sidewall Height: 5.75 in -or- 146.05 mm

I couldn't find the diameter for the 18 or 19 tire...but...I doubt they are "bigger" or more specifically have a larger diameter
I imagine the sidewall height on the 18 and 19 are shorter to keep final drive ratios the same/similar for all rim sizes to maintain mpg considerations (and probably tow rating as well)
Well only one is bigger (diameter): These measurments are with the factory size tires only.

18 inch rim, has 28.17 diameter or 715.51mm
19 inch rim, is 29.17 diameter or 740.91mm

So for ie. if you have the 17's and want 18's your speedo will read 1.2% faster than actual speed as the 18's have a smaller total diameter than the 17's.
However, if you have 17's and would like to upgrade to the 19's, your speedo will read 2.3% slower as the total wheel diameter is larger.
If you have the 18's and want 19's then your speedo will be reading 3.5% too slow.
Hope that helps.
You may want to look at the difference in price between the 18's and 19's when you have to replace the tires. One sales person told me she felt the 18's gave a softer ride compared to the 19's.
Every car magazine review I've read the reviewer always says that the smaller diameter wheel gives a softer ride.
I know the 19" wheels I have on the Terrain give a lot harsher ride compared to the 17" wheels I had on my Aztek.
GARYD said:
Every car magazine review I've read the reviewer always says that the smaller diameter wheel gives a softer ride.
I know the 19" wheels I have on the Terrain give a lot harsher ride compared to the 17" wheels I had on my Aztek.
I call the ride on my 19" wheels firm but not objectionable. Then again I like the ride on my Corvette with the Z-51 suspension so maybe I'm not a good judge of ride quality.
GARYD,

Have you ever thought about replacing your 19" with 18"?

It looks like 99% of the locally available SLT-2 V6s are coming with 19" wheels now (Houston area). It's looking more and more like I'll have to order (which means I probably won't get the loyalty bonus since that ends on Monday). GRRRRR.
I was thinking on doing just that when the time comes to replace the tires, but I don't know what the charges would be to re calibrate the computer.

Black Granite, I don't object to harsh rides, like you I've had a couple Vettes and I expect them to have a harsher suspension, not a cushy family car. Could you imagine a Vette with the suspension of a big family car...it would be all over the road.
When I race I want tires that I can drive over a dime and be able to tell what year it is. LOL
We just got our Terrain about a month ago and I got the 19's. It doesn't ride harsh at all and there are no tire noises or anything.
GARYD said:
I was thinking on doing just that when the time comes to replace the tires, but I don't know what the charges would be to re calibrate the computer.
No charge I believe. You may want to check with your GM Tech first, but as I posted earlier - GM GDS computer doesn't have a provision to downsize from 19's to 18's. Only when upsizing can they recalibrate. [/color]
We just got our Terrain about a month ago and I got the 19's. It doesn't ride harsh at all and there are no tire noises or anything.
What tires are you running ! I have a 2019 equinox premier with 19in Han kooks very rough ride !
This thread is 10 years old.
BTW in the 2010-2017 body style, some of the front suspension components are different with the factory 19 inch wheels.
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