18" vs 19" wheels

[Jeff Lampert]

Hello everyone, I just joined the forum. I have owned Nissans for many years. I am very close to purchasing an Infiniti Ex. I test drove one and like it a lot. Here's my issue. I want the Tech package but to get it I have to purchase the Touring package which comes with 19" wheels. While I have not driven the 19" wheels I have read in a few places that the ride is stiffer than with the 18". I am quite sure I will much prefer the 18" wheels with the better ride. A dealer will swap out the wheels for me but I need to know if there are any ramifications to this, with respect to such things as the speedometer reading, tire pressure gauge, transmission and suspension settings, etc. etc.

Your help and advice is much appreciated. Thank you. .. Jeff

[jmess]

No ramifications. Wheels and tires will be lighter which is good.

[Jeff Lampert]

Thanks for your reply. (BTW, I'm getting it with AWD). Does this mean that the transmission and suspension are exactly the same for both the 18" and 19" wheels. i.e. the Touring package does not affect any of this? I was told that the speedometer reading might be off by a couple of miles per hour if the 19" wheels are swapped for standard 18". Does that make any sense? Thanks again.

[Tasman]

Why not test drive the EX with the 18 inch and the 19 inch wheels to judge for yourself?

[RedwinGV]

Thanks for your reply. (BTW, I'm getting it with AWD). Does this mean that the transmission and suspension are exactly the same for both the 18" and 19" wheels. i.e. the Touring package does not affect any of this? I was told that the speedometer reading might be off by a couple of miles per hour if the 19" wheels are swapped for standard 18". Does that make any sense? Thanks again.

I doubt if the speedo would be off. The tires would be a lower profile, so they radius would be the same. With that being said, one would expect a rougher ride but more stability with 19s vs the 18s. I noticed some when I drove one with 17s vs 18s. Not much though. But, 19's have an even lower profile tire, so yeah I would expect a rougher ride.
As for the transmission and Suspension, I suspect they are the same for 19 or 18 rims. I say this since I was thinking of swapping for 17s (but never did) and mys salesrep said there was no diff in the 2010.

[DDS]

I tried to buy an EX last October and ran up against the fact that you can't order a loaded EX without the 19" wheels. In my case i thought they looked ridiculous - like something my teenage son would have put on his car. But those things, being subjective, I simply offered to pay what ever it cost for the dealership to mount 18" wheels and tires on a loaded car - and they flat out refused to have any part in such a scandalous venture (really). So I am a proud owner now of a Lexus. I am still looking for an EX. Love the car.

There is ABSOLUTELY no reason you can't mount 18" wheels from a 2010 or 2011 EX on your car. Just make sure they are factory wheels that are new, or used wheels that have been professionally inspected and certified to be in good condition. Do not accept used wheels that have been straightened.

Wheels that use the 45 series tires can be a serious safety concern because there is so little air volume in the tires you must insure you have full tire pressure at all times. The car manufacturers that use theses tires all include disclaimers in their sales literature that say you must check the air pressure continuously. Motor Week even had a segment on this hazard a few months ago. If you would hit a pot hole running 19" wheels with 45 series tires the odds would be extremely high you would damage the wheel and experience a blow out.

Infinity is a company that has always pandered to trending. In a way that is great because they have come up with some cars way ahead of their time like the EX. In another, it is bad because they will ruin their own great designs by any silly fad that comes along.

[jmess]

I think you forgot to consider tire and rim width in your assumptions about tire air volume. A 19x8.5 wheel with a 245-45-19 tires has a larger tire/air volume than a 18x8 inch wheel with a 225-55-18 tire. Also we have tire pressure monitoring systems that watch tire pressure for us.

The world is full of risks but you can bet Nissan considers the trade off between ride, handling, and safety when they added the 19s as an option. So there are a lot of reasons not to like or want 19s but the fear factor isn't one of them IMHO.

[Jeff Lampert]

I think you forgot to consider tire and rim width in your assumptions about tire air volume. A 19x8.5 wheel with a 245-45-19 tires has a larger tire/air volume than a 18x8 inch wheel with a 225-55-18 tire. Also we have tire pressure monitoring systems that watch tire pressure for us.

The world is full of risks but you can bet Nissan considers the trade off between ride, handling, and safety when they added the 19s as an option. So there are a lot of reasons not to like or want 19s but the fear factor isn't one of them IMHO.

What possible reason would Nissan have for including larger rims in a Touring package which is about comfort and convenience? The larger wheels reduce ride comfort. It seems the only reason is appearance.

[DDS]

I think you forgot to consider tire and rim width in your assumptions about tire air volume. A 19x8.5 wheel with a 245-45-19 tires has a larger tire/air volume than a 18x8 inch wheel with a 225-55-18 tire. Also we have tire pressure monitoring systems that watch tire pressure for us.

The world is full of risks but you can bet Nissan considers the trade off between ride, handling, and safety when they added the 19s as an option. So there are a lot of reasons not to like or want 19s but the fear factor isn't one of them IMHO.

I didn't forget to consider width, but my description of the problem was not accurate. The problem is not volume alone. The problem is when a 2 under tire loses air, there is little or no ability for that tire to adsorb the blow of a pot hole, and the rim hits the concrete. At high speeds the impulse force that results is huge and the rim will bend, severely in many cases. This is not an opinion. Motor Week as mentioned above, has issued warnings about these tires as well as Consumers reports. Keeping those tires fully inflated minimizes the chance of a blowout. But who here has not experienced losing air totally unexpectedly? Why would thin cross sectioned tires be any different? Couldn't help but notice when I bought my Lexus that they now offer insurance to cover these kind of incidents. Never recall any dealer offering insurance like that in the past.

[jmann]

Wow, if you were in my state I would offer to let the dealer trade my 18's for your 19's. There really isn't a practical way to do this over a long distance though...