Optimal Wheel Size for Stock Power

[mrk1]

17x7 with better factory size rubber

[rainmonkey]

Originally Posted by ST185RC

It's not as simple as that. When it comes to wheels and tires, it depends on what you want. If you want more road feel, you will want a shorter sidewall while increasing the rim diameter. This will give an overall more rigid wheel. Then you have people that want larger wheels just for looks.

Smaller wheel does not necessarily mean it's better for speed. A smaller wheel usually means lighter and less unsprung weight that the engine and brakes need to accelerate or decelerate. It could mean that it's quicker getting in and out of turns as it takes less effort for the engine to rotate the smaller mass. The lighter the wheel, the later you can brake (generally speaking) and carry more speed through a corner.

For rolling speed, a larger diameter wheel vs smaller diameter wheel, holding the sidewall height and total weight the same, the larger diameter wheel is faster based on the angular displacement for every revolution that the wheels turn, it's angular velocity. That is, for the same number of times the wheels rotate, the larger wheel will cover more distance in the same amount of time. This is assuming that the engine is doing the same output to move the wheel masses.

Damn, lots of info there...very informative, thank you. But it only makes it harder for for me to reach a conclusion on what diameter to get lol

[jam0o0]

st185rc posted some good info. just don't forget that you lose torque and gain top speed when your tire OD gets larger.

the big power big circuit cars run big wheels so they can fit large brakes to deal with the enormous heat. IMO the smallest wheels that will fit over the smallest brakes you can get away with with the widest and stickiest tire is the best you can get.

i use my FR-S in autocross. the factory brakes have never gotten too hot on a course yet. and i know we can fit 16's. 245 is the widest tire i can get that fits my rule-set that fits a 16. so that's my formula.

[WolfSongX]

The Road and Track test showed that two different diameter wheels of a similar mass running the same compound and design of performance tire, the 17" tire was several 10ths quicker than the 18". All other factors being equal, this means that the difference in the rotational mass is significant at the stock power levels. This was also backed up by the test drivers noting that the car was more sluggish at certain points.

With the basic bolt-ons and a tune, these cars don't tend to make a lot of extra power unless you go FI, so by going to 18" rims and increasing your rotational mass, you are in fact giving up the power you did gain with your other mods.

Personally, my first choice would be some super lightweight forged 17x8's or 17x7.5's so I can run a 225 series tire and have a slightly bigger contact patch than the 215's, but mainly to take advantage of the slightly cheaper rubber options when I have to replace the tires, especially since forged rims are so freaking expensive.

However since I rarely get to the track or autocross these days, then I can consider this to be just a street application only. That way I can drop the ultra-light and expensive forged wheels from my criteria since the extra couple of pounds per wheel isn't going to matter as much. Instead I can look at just doing cool-looking inexpensive 17's that are lighter than the stock wheels and will cost a fraction of what the forged wheels cost. As long as they're a few pounds lighter than the stock wheels, there will not be a performance decrease, even with heavier/wider tires and I can take advantage of stickier rubber on a slightly wider rim.

[Gary in NJ]

I've been giving a lot of thought to tires and wheels. My priority is performance over aesthetics. Also, my car will not see track or autocross duty. My sole "give-in" to aesthetics is going with a wheel that pushes the wheel closer to a flush fit. In this regard my wheel search has included wheels in the +35 off-set range.

In my search I've been weight obsessed. I haven't given any consideration to a tire/wheel that can't save a minimum 10% over stock; 15% is my goal. Also, since this is a street-only car, for tire selection I've put more of a priority on ride quality and predictability versus ultimate grip. Looking at summer tire comparisons on Car & Driver and Tire Rack has served as my method of research.

As a quick reference, the stock wheel is a 17x7 +48 that weighs 21.4 pounds. Stock tire is 215/40-17 weighing 20 pounds for a total installed weight of 41.4 pounds.

If you want to search for 17x8 +35 5x100 wheels on Tirerack, choose a 2004 Dodge Neon SRT-4 as your search vehicle. If you search on any of the -86's you return mostly +48 wheels. In my search for wheels several have caught my attention due to their low weight. All of these wheels are 17x8:

Kosei K1-TS +35 @ 15.1 lbs
Kosei K4R +35 @ 15.8 lbs
Enkei RPF1 +35 @ 16.1 lbs
TSW Interlagos +35 @ 17.1
Enkei PF01 +38 @ 17.3 lbs
TSW Nurburgring +35 @ 17.95 lbs

So I have a significant weight reduction of the stock wheels, in a wider size. Weight savings range from 6.3 to 3.45 lbs (29% to 16% weight savings). But here is where most everyone makes the critical error; tire selection.

Some of the most popular tires completely give back any weight savings that the wheels provide...some gain weight. For example, in a 225/45-17:

Potenza RE760 @ 27lbs
Dunlop SP Sport 01 @ 27 lbs

There are some light weight tires in 225/40 that weigh the same or close to the stock 215/45's, these include:

Continental ExtremeContact DW @ 20lbs
Pirelli Cinturato P7 @ 20lbs
Dunlop Sport Maxx RT @ 21 lbs
Michelin Pilot Sport PS2 @ 22 pounds

Combining the Kosei K1-TS and a ExtremeContact yields an installed weight of 35.1 pounds; a savings of 6.3 pounds (15.2%). The similar looking (and widely popular) Enkei RPF1 yields an installed weight of 36.1 pounds; a savings of 5.3 pounds (12.8%). The only knock I have on the K1-TS & RPF1 is that the design has a visual effect of looking smaller then its size would suggest. The barrel has a raised area that the spoke attach...making the spokes appear short. Alas, the K1-TS seems to be the Unicorn wheel in the US. Kosei's website lists it with a +35 offset, but the sole US distributor (Tirerack) doesn't.

My favorite of the wheels is the TSW Nurburgring, but at an installed weight of 37.95 lbs they only offer an 8% weight savings. That's a lot of money spent for little return.

I also noticed that there is a weight penalty for choosing an et35 over an et48...about 0.2 to 0.5 pound per wheel. This is because most manufacturers (in the budget range) simply have a thicker mounting surface (rear side) rather then actually move the barrel towards the outside. Hey, ya get what ya pay for. Most of these wheels are in the $200 to $250 range. I can't see paying $350+ to save 0.2 pounds.

At this point I'm leaning towards the Kosei K4R/ExtremeContact combination which is close to my overall goal (5.6 lbs per wheel or 13.5%). As a bonus the wheels are available in Light Gray, which I think will provide a nice contrast on my WRB BRZ. More bonus...the center caps are only $15 each versus $26 each for the Enkei's.

That's my $0.02

[hmong337]

I plan to run a square setup with 17x9 on sticky 245/40/17. I like the 18"s aesthetically but the cost difference in tires compared to 17" turns me off.

[Lee358]

Originally Posted by Gary in NJ

I've been giving a lot of thought to tires and wheels. My priority is performance over aesthetics. Also, my car will not see track or autocross duty. My sole "give-in" to aesthetics is going with a wheel that pushes the wheel closer to a flush fit. In this regard my wheel search has included wheels in the +35 off-set range.

In my search I've been weight obsessed. I haven't given any consideration to a tire/wheel that can't save a minimum 10% over stock; 15% is my goal. Also, since this is a street-only car, for tire selection I've put more of a priority on ride quality and predictability versus ultimate grip. Looking at summer tire comparisons on Car & Driver and Tire Rack has served as my method of research.

As a quick reference, the stock wheel is a 17x7 +48 that weighs 21.4 pounds. Stock tire is 215/40-17 weighing 20 pounds for a total installed weight of 41.4 pounds.

If you want to search for 17x8 +35 5x100 wheels on Tirerack, choose a 2004 Dodge Neon SRT-4 as your search vehicle. If you'll search on any of the -86's you return mostly +48 wheels. In my search for wheels several have caught my attention due to their low weight. All of these wheels are 17x8:

Kosei K1-TS +35 @ 15.1 lbs
Kosei K4R +35 @ 15.8 lbs
Enkei RPF1 +35 @ 16.1 lbs
TSW Interlagos +35 @ 17.1
Enkei PF01 +38 @ 17.3 lbs
TSW Nurburgring +35 @ 17.95 lbs

So I have a significant weight reduction of the stock wheels, in a wider size. Weight savings range from 6.3 to 3.45 lbs (29% to 16% weight savings). But here is where most everyone makes the critical error; tire selection.

Some of the most popular tires completely give back any weight savings that the wheels provide...some gain weight. For example, in a 225/45-17:

Potenza RE760 @ 27lbs
Dunlop SP Sport 01 @ 27 lbs

There are some light weight tires in 225/40 that weigh the same or close to the stock 215/45's, these include:

Continental ExtremeContact DW @ 20lbs
Pirelli Cinturato P7 @ 20lbs
Dunlop Sport Maxx RT @ 21 lbs
Michelin Pilot Sport PS2 @ 22 pounds

Combining the Kosei K1-TS and a ExtremeContact yields an installed weight of 35.1 pounds; a savings of 6.3 pounds (15.2%). The similar looking (and widely popular) Enkei RPF1 yields an installed weight of 36.1 pounds; a savings of 5.3 pounds (12.8%). The only knock I have on the K1-TS & RPF1 is that the design has a visual effect of looking smaller then its size would suggest. The barrel has a raised area that the spoke attach...making the spokes appear short. Alas, the K1-TS seems to be the Unicorn wheel in the US. Kosei's website lists it with a +35 offset, but the sole US distributor (Tirerack) doesn't.

My favorite of the wheels is the TSW Nurburgring, but at an installed weight of 37.95 lbs they only offer an 8% weight savings. That's a lot of money spent for little return.

I also noticed that there is a weight penalty for choosing an et35 over an et48...about 0.2 to 0.5 pound per wheel. This is because most manufacturers (in the budget range) simply have a thicker mounting surface (rear side) rather then actually move the barrel towards the outside. Hey, ya get what ya pay for. Most of these wheels are in the $200 to $250 range. I can't see paying $350+ to save 0.2 pounds.

At this point I'm leaning towards the Kosei K4R/ExtremeContact combination which is close to my overall goal (5.6 lbs per wheel or 13.5%). As a bonus the wheels are available in Light Gray, which I think will provide a nice contrast on my WRB BRZ. More bonus...the center caps are only $15 each versus $26 each for the Enkei's.

That's my $0.02

Wow lots of thought went into that... If you want to see 17x9 +45 rpf1s with 245/40/17 on the brz let me know im in jersey also

[RC51rydr]

Originally Posted by Gary in NJ

I've been giving a lot of thought to tires and wheels. My priority is performance over aesthetics. Also, my car will not see track or autocross duty. My sole "give-in" to aesthetics is going with a wheel that pushes the wheel closer to a flush fit. In this regard my wheel search has included wheels in the +35 off-set range.

In my search I've been weight obsessed. I haven't given any consideration to a tire/wheel that can't save a minimum 10% over stock; 15% is my goal. Also, since this is a street-only car, for tire selection I've put more of a priority on ride quality and predictability versus ultimate grip. Looking at summer tire comparisons on Car & Driver and Tire Rack has served as my method of research.

As a quick reference, the stock wheel is a 17x7 +48 that weighs 21.4 pounds. Stock tire is 215/40-17 weighing 20 pounds for a total installed weight of 41.4 pounds.

If you want to search for 17x8 +35 5x100 wheels on Tirerack, choose a 2004 Dodge Neon SRT-4 as your search vehicle. If you search on any of the -86's you return mostly +48 wheels. In my search for wheels several have caught my attention due to their low weight. All of these wheels are 17x8:

Kosei K1-TS +35 @ 15.1 lbs
Kosei K4R +35 @ 15.8 lbs
Enkei RPF1 +35 @ 16.1 lbs
TSW Interlagos +35 @ 17.1
Enkei PF01 +38 @ 17.3 lbs
TSW Nurburgring +35 @ 17.95 lbs

So I have a significant weight reduction of the stock wheels, in a wider size. Weight savings range from 6.3 to 3.45 lbs (29% to 16% weight savings). But here is where most everyone makes the critical error; tire selection.

Some of the most popular tires completely give back any weight savings that the wheels provide...some gain weight. For example, in a 225/45-17:

Potenza RE760 @ 27lbs
Dunlop SP Sport 01 @ 27 lbs

There are some light weight tires in 225/40 that weigh the same or close to the stock 215/45's, these include:

Continental ExtremeContact DW @ 20lbs
Pirelli Cinturato P7 @ 20lbs
Dunlop Sport Maxx RT @ 21 lbs
Michelin Pilot Sport PS2 @ 22 pounds

Combining the Kosei K1-TS and a ExtremeContact yields an installed weight of 35.1 pounds; a savings of 6.3 pounds (15.2%). The similar looking (and widely popular) Enkei RPF1 yields an installed weight of 36.1 pounds; a savings of 5.3 pounds (12.8%). The only knock I have on the K1-TS & RPF1 is that the design has a visual effect of looking smaller then its size would suggest. The barrel has a raised area that the spoke attach...making the spokes appear short. Alas, the K1-TS seems to be the Unicorn wheel in the US. Kosei's website lists it with a +35 offset, but the sole US distributor (Tirerack) doesn't.

My favorite of the wheels is the TSW Nurburgring, but at an installed weight of 37.95 lbs they only offer an 8% weight savings. That's a lot of money spent for little return.

I also noticed that there is a weight penalty for choosing an et35 over an et48...about 0.2 to 0.5 pound per wheel. This is because most manufacturers (in the budget range) simply have a thicker mounting surface (rear side) rather then actually move the barrel towards the outside. Hey, ya get what ya pay for. Most of these wheels are in the $200 to $250 range. I can't see paying $350+ to save 0.2 pounds.

At this point I'm leaning towards the Kosei K4R/ExtremeContact combination which is close to my overall goal (5.6 lbs per wheel or 13.5%). As a bonus the wheels are available in Light Gray, which I think will provide a nice contrast on my WRB BRZ. More bonus...the center caps are only $15 each versus $26 each for the Enkei's.

That's my $0.02

Very informative....thank you!!

[Panman]

Originally Posted by WolfSongX

Personally, my first choice would be some super lightweight forged 17x8's or 17x7.5's so I can run a 225 series tire and have a slightly bigger contact patch than the 215's, but mainly to take advantage of the slightly cheaper rubber options when I have to replace the tires, especially since forged rims are so freaking expensive.

This. I'm currently running 17x8 Desmond Regamaster Marquis Promada with 225/45. (Look em up for those unfamiliar with the fine art of Russian forged wheels)


Previously on 18x8 OZ UltraLeggeras 225/40 the OZs were light(ish) but the Desmonds make a noticeable difference.

[vuthatswho]

Originally Posted by Kairos

The problem is not that they are 18's, it's that you bought 28+ lb. wheels. Get a 18x9 that weight 18 lbs and I guarantee you'll see a huge difference. I believe the stockers are 20-22 lbs so you added alot of extra weight to rotate.

Thanks forgot about something so simple haha I was second guessing my ze40s LOL

[churchx]

I'd wish to vote for 17x7 or 17x7.5 .. or 16x7 .. but none of those were listed.

[Adam_L]

I agree with ChurchX

To me that is optimal. Lighter weight is king not just for better 0-70 times, or carving , but also better for MPG get up and go.

That video on pg. 1 was informative. Even if you go 18" , on a good forged wheel, anything quality will weight 16-18 lbs. On a 16x7, you can get weight down to 10.5- 11.2 lbs (SSR Type-C or Volt TE-37) , or even a good forged 17x7 , weight will be about 13.5- 14lbs for something upper level.

Going 18" or 19" is more of a bling bling thing. The car was designed around a 17" wheel, plain and simple. A 16" wheel could be good in that it's lighter, but needs to set up right so you have a similar diameter as the stock wheel (so maybe a 215/ 50/ 16 tire size (have to check the comparison wheel conversion calculators that are online ) : http://www.1010tires.com/Tools/Tire-Size-Calculator

[Lynxis]

Originally Posted by Adam_L

I agree with ChurchX

To me that is optimal. Lighter weight is king not just for better 0-70 times, or carving , but also better for MPG get up and go.

That video on pg. 1 was informative. Even if you go 18" , on a good forged wheel, anything quality will weight 16-18 lbs. On a 16x7, you can get weight down to 10.5- 11.2 lbs (SSR Type-C or Volt TE-37) , or even a good forged 17x7 , weight will be about 13.5- 14lbs for something upper level.

Going 18" or 19" is more of a bling bling thing. The car was designed around a 17" wheel, plain and simple. A 16" wheel could be good in that it's lighter, but needs to set up right so you have a similar diameter as the stock wheel (so maybe a 215/ 50/ 16 tire size (have to check the comparison wheel conversion calculators that are online ) : http://www.1010tires.com/Tools/Tire-Size-Calculator

Lower spec models of the 86 in Europe and Asia come with 205/55r16s on a 16x6.5 rim so you can definitely run 16s if you want. You could definitely do a 215/50r16 instead too.