19" vs. 18" Wheels/Tires

[DenverSteve]

Can anyone of you who have switched from 18" wheels/tires to a 19" set please comment on the difference in handling/performance? I currently have my stock 18's but would like to know the performance difference.

Thanks.

[Johnny Danger]

You'll find that there are highly polarized views on the topic. However, few will argue that the common goal is to reduce unsprung weight and rotational while not compromising strength and reliability . Personally, I run 19's on my vehicle. And, for the reasons previously mentioned, I am very pleased with how they perform over the oem 18's . That's not to say that I couldn't have accomplished the same with 18's, however, the set that I have now met all of the criteria .

[DenverSteve]

Thanks Johnny - and I agree - but then 17's would be even lighter. Is there any consensus on the best performance combination for tire/wheel size?

[Topless]

The fastest Boxsters on the west coast are on 17s. The new lightweight Boxster Spider 19s are pretty good and comparable in performance but the tires are 2X the price of the same width in 17 inch and selection of quality 19" tires is still limited. Those drivers that shred a lot of race rubber run 17s for that reason.

[Johnny Danger]

Originally Posted by Topless

The fastest Boxsters on the west coast are on 17s. The new lightweight Boxster Spider 19s are pretty good and comparable in performance but the tires are 2X the price of the same width in 17 inch and selection of quality 19" tires is still limited. Those drivers that shred a lot of race rubber run 17s for that reason.

Certain that it is , 17's are far more appropriate for track use than 19's . There's simply not enough rubber to run 19's under those conditions . However, for street "tuning" there's a practical application for running lighter, larger diameter wheels .

[DenverSteve]

Originally Posted by Johnny Danger

Certain that it is , 17's are far more appropriate for track use than 19's . There's simply not enough rubber to run 19's under those conditions . However, for street "tuning" there's a practical application for running lighter, larger diameter wheels .

What wheels are you running?

[jbs986]

Originally Posted by Johnny Danger

Certain that it is , 17's are far more appropriate for track use than 19's . There's simply not enough rubber to run 19's under those conditions . However, for street "tuning" there's a practical application for running lighter, larger diameter wheels .

+ 1, 17's faster on the track, I use 17's on the track and 18's for the street.

[Johnny Danger]

Originally Posted by DenverSteve

Thanks Johnny - and I agree - but then 17's would be even lighter. Is there any consensus on the best performance combination for tire/wheel size?

Not necessarily, as far as I know my aftermarket 19's are lighter than any oem 17's .

[Topless]

Originally Posted by Johnny Danger

Not necessarily, as far as I know my aftermarket 19's are lighter than any oem 17's .

Really? My 17s are 19lbs -F and 21.5-R. I have seen some exotic high $$$ 19 wheels that were lighter but it is rare. I have also seen some 35lb 19" replicas .

[ekam]

18" vs 19" Comparison - The Pros & Cons of your track tire- Best Motoring International - YouTube

[Pat]

Originally Posted by ekam

18" vs 19" Comparison - The Pros & Cons of your track tire- Best Motoring International - YouTube

That video is a joke. While I like the intent, the "study" is executed poorly. The idea is to compare the performance of 18" wheels with that of 19" wheels. In order to do that, one must isolate all other variables. They did not do this. The only changes in the front wheels are diameter, which is perfect for the goal of this video. However, the 19" rear wheels are an inch wider than the 18" wheels. That alone can skew the results due to size and weight factors. Moreover, the front tires on the 19" wheels are 20mm wider than those on the 18" wheels. Even worse, the rear tires on the 19" wheels are 30mm wider than those on the 18" wheels. That's totally skews the results.
The cherry on top is when the test driver says, "I can feel the rolling resistance." Yeah...sure you can.

Ceteris paribus, if your top priority is performance, go smaller. If you care more about appearance, go bigger. Done.

[Johnny Danger]

Nobody runs 19's at the track . That's a given . We're talking about street applications here .

[ekam]

Originally Posted by Pat

That video is a joke. While I like the intent, the "study" is executed poorly. The idea is to compare the performance of 18" wheels with that of 19" wheels. In order to do that, one must isolate all other variables. They did not do this. The only changes in the front wheels are diameter, which is perfect for the goal of this video. However, the 19" rear wheels are an inch wider than the 18" wheels. That alone can skew the results due to size and weight factors. Moreover, the front tires on the 19" wheels are 20mm wider than those on the 18" wheels. Even worse, the rear tires on the 19" wheels are 30mm wider than those on the 18" wheels. That's totally skews the results.
The cherry on top is when the test driver says, "I can feel the rolling resistance." Yeah...sure you can.

Ceteris paribus, if your top priority is performance, go smaller. If you care more about appearance, go bigger. Done.

When you upsize, you're inherently going wider as well. For example, while you can get 7" wide, 17" wheels, you cannot find 7" wide, 19" wheels. Of course when you go wider wheel, you have to get wider tires. Hence the reason why if you have 17" you're running 255 rears, and for 18" you're running 265 rears and so on. In fact, that's the whole idea of upsizing... you should read up the tech article at TireRack.com.

The point of their exercise is that going wider & larger wheel which theoretically provide more traction & grip, does not provide better driver feedback and marginally quicker track time even in the hands of a professional driver.

[jmatta]

Johnny...I want some of those Salmon steaks!

As always, your car is a real looker...

[Johnny Danger]

Originally Posted by jmatta

Johnny...I want some of those Salmon steaks!

As always, your car is a real looker...

I was thinking of adding some salmon steaks to the front spoiler . What do you think ?

[Mrmaddbrad]

Originally Posted by Johnny Danger

I was thinking of adding some salmon steaks to the front spoiler . What do you think ?

Just run them as spacers. Performance Achieved!

[DenverSteve]

Thanks Johnny. Post 18 is what I was hoping for. I can easily "chart" the difference in height and width on any tire converter. That doesn't give me the Boxster application I need. Both this and my first Boxster have always run factory wheels and tires. It's a little different than changing out the 32's on my Wrangler.

[Pat]

Ekam, I disagree with your statement, "When you upsize, you're inherently going wider as well." There are plenty of 16" wheels out there that are wider than the stock Boxster 17" wheels. Additionally, there are plenty of wheels out there that allow custom barrel sizing and custom diameter. While I will agree most of the time taller wheels are also wider, saying the two factors are inherently coordinated is absolutely false.

[ekam]

Well disagree all you want but fact is almost all wheel manufacturers do not offer custom sizing (even so, it will not be at a price you and I can afford.) Add variables like wheel offsets and bolt patterns you're stuck with what they offer and that's that. Take a look at sites like Tirerack and see it yourself.

[stephen wilson]

Well, the factory 18's and 19's have the same section width, so no, it's not mandatory to go wider. He said the 19's are MORE sensitive, more like a race car, but that sensitivity may not result in quicker lap times for most drivers. The other problem is the Z wasn't designed for 19" tires, which are much more camber sensitive. Results will vary depending on the car in question.