Bigger Wheels How Much Slower?

[CowPimp]

How much slower would it be to move from the stock 205/50/16s to a set of 225/40/18s (1/4 difference?)? Also, is handling a lot better with bigger wheels? In addition, wouldn't the car accelerate better at higher speeds? Also, since the tires are more low profile, would it even out since the total wheel diameter would be close to the stock setup?

 

[kn69]

Go here.... http://www.miata.net/garage/tirecalc.html

 

[CowPimp]

Thanks, but that really only tells me how much the speedometer is off. It does give the number of revolutions per mile, but it still doesn't really tell me how much slower it will be. I'm guessing it's not really that much slower. Maybe .2-.3 off a 1/4 time?

 

[BlueSexMachine]

Find some 17 or 18 inch rims that are lightweight. Like the Rotas seen here:http://machiii.net/machiii/html/Rota_wheels.html

 

[cOiL]

Originally posted by CowPimp
How much slower would it be to move from the stock 205/50/16s to a set of 225/40/18s (1/4 difference?)? Also, is handling a lot better with bigger wheels? In addition, wouldn't the car accelerate better at higher speeds? Also, since the tires are more low profile, would it even out since the total wheel diameter would be close to the stock setup?

No, it won't accelerate better at any speed. It's probably gonna be heavier and a heavy thing is gonna take more engery to accelerate them... A 14" wheel that weighs 10 lbs will require less engery to turn than a 17" wheel that weighs 10 lbs. It's cause the mass is further away from the center. That's why iceskaters tuck themselves in while they sping around so quickly. I dun remember the technical terms for all of that, so someone else can help me there. I dunno if the weight saved on the less ruber needed for the tire on that same 17" wheel would make up for the 17" wheel though. I also dont know if you can understand what I just said. I'm even having a hard time figuring that one out.

-j

 

[CowPimp]

No, I understand that part very well. I know why the car goes slower. It is because of rotational inertia (How hard it is to turn the wheel); this is increased as the mass is moved further from the center.

Now, in my post, I was look for actual track time measurements or some kind of tangible difference (1/4 time, 0-60, something). I want better handling at the cost of acceleration, but not a lot of acceleration.

 

[1gawddsm]

when moving to bigger rims the tire profile decreases, optimally you can get a very close match between your stock overall diamter and the new bigger rims overall diameter with tire. NOW when you have 11-12 lb rims that are 15's, the fat tires on them weigh more than the rim (my kosei k1's with tires weigh 35 lbs inflated), therefore much more of the overall rim/tire mass is on the outside edge in the tire, NOW with a 17-18 inch rim with a low profile tire more mass is focused toward the center/rim, not on the tire, ,,,when an ice skater pulls his arms in while spinning he accelerates because more mass is closer to his center rotational point.

 

[RoadRacingDSM]

A guy on 2gnt...........ran a 16.1 with his RS. When he put on his 18's with 225/40/18 tires....he ran a 16.7. So it can be a large difference, but then again it depends on the weight of the wheel a lot.

 

[CowPimp]

Ouch, that puts a hurting on the 1/4 time, but more information is needed to make a definitive conclusion.

What size tire did your friend have originally? Were the 18 inch while lightweight? Were the stock wheels lightweight?

This is important to know because I would be moving from stock wheels from a 2G Turbo to lightweight 18x8 inch rims. Possibly 17 inches.

 

[AP-Signworks]

It's going to be kind of hard to quantify since a lot of other issues play into it. Traction is always going to be a factor. And did the guy make his runs back to back? Or on separate nights.

Originally posted by CowPimp
Ouch, that puts a hurting on the 1/4 time, but more information is needed to make a definitive conclusion.

What size tire did your friend have originally? Were the 18 inch while lightweight? Were the stock wheels lightweight?

This is important to know because I would be moving from stock wheels from a 2G Turbo to lightweight 18x8 inch rims. Possibly 17 inches.

 

[DeezNutsForYou]

I decided to get 18's on my car, and I did notice a small change. There is obviously some power loss, but not much. And the way that they handle definetely makes up for it. My wheels are also 25lbs, thats really heavy, you can get 17's from weld that weight somewhere around 11 or 12 pounds. And just the looks alone are worth it, but I know that doesn't mean much to some of these die hard racers.

 

[DeezNutsForYou]

One thing I wanted to ask is how much overall height makes a difference. If two wheels and tires are the same weight, but one is a 215/60/16 and one is a 195/50/16. How much would that inch of overall tire height be. Has anyone tested this to see what gear ratio that would give you, and how it would effect the quarter.

 

[mrecl1pse]

I can tell you lightweight wheels makes big difference. Sorry I don't have any real numbers for comparisons, which I wish I had done before I sold my old wheels. I used to have a set of 18x7.5" quantum tek rims with Dunlop SP Sport W-10s and I upgraded to 18x8" Volk Racing GT-Cs with Goodyear Eagle GS-D3s. Just by picking up the wheel, I could feel by hand the considerable lightness of the forged Volks vs. the cast quantum teks. Driving, it feels like there is a differences in acceleration with the lighter wheels (though could be placebo), but I've noticed that my mileage has gone up about 2 mpg (which I think is significant).

On another note, a friend of mine, upgraded his stock wheels on his VW Passat from the stock 15" aluminum alloy rims to Oettinger 18x8" (which I think are 25lbs/ea) and he consistently lost about 3 mpg according to his mpg display on his dash.

 

[RST]

How much slower. I ran my car in the quarter with my stock wheels 14's and I ran it with curent wheels 19's. The diference was .41.

at almost half a second it is very noticeable. But when it comes to the handleing it is just so much better that I can't even think of a comparison for the 2.

My speedomiter is off by about 5 mph.

 

[Keaka26]

its not really the height of the wheel that makes handling better, its the width that usually comes with height. Wider wheels usually have a wider tire. wider tire = bigger contact patch. bigger patch = more grip. more grip = better handling (usually).

The car goes slower not only because of weight, but also because the final drive ratio of the car also changes with a tall wheel/tire setup. Obviously, shorter gears will go a lot faster.

 

[Eagle 5]

One thing I wanted to ask is how much overall height makes a difference. If two wheels and tires are the same weight, but one is a 215/60/16 and one is a 195/50/16. How much would that inch of overall tire height be. Has anyone tested this to see what gear ratio that would give you, and how it would effect the quarter.

i have a calculator on excel that you enter in your gear ratios and tire size and it tells you the speed of your car in each gear at 1k rpm intervals. and oyu can put a diff size tire on and compare the speeds of them. its nice. if anyone wants it, PM me or email me at [email protected]

 

[CowPimp]

I went with ADR RS Limited Concept Pros. They are about 18 pounds, 17x7", and they look pretty good too. I was going to go with the Subzeros, but I was able to get a deal with the tires already mounted with these. I think the 4 pound weight difference should make up for the larger wheel. After all, the total diameter is going to be about the same, and tire weight is pretty significant as well.

 

[Wikkedson]

It seems like with a smaller diameter overall for the wheel and tire makes a difference in acceleration.
It pretty much changes up the gearing. You will either reach a certain mph faster or slower.
Like say you had a stock 2g 205/55/16 tire. If you went with a 205/45/16 you would accelerate faster because of the smaller overall diameter. Which would be good for drag racing.
If you have fwd this can be bad, because the tires do not have to travel as far and will break loose easier.
Also add in the fact of less weight in the tire and less side wall.
Lighter wheels also do make a huge difference.
When i switched from stock 5 star gst wheels to my Te-37s it was a very noticable difference.
I run 215/45/16 tires, but it makes the fender gap look HUGE.
But it handles well (stiffer sidewall on 45 series tire) and accelerates faster (Smaller overall diameter).
I hope that all made sense. For all those who read it.

 

[CowPimp]

Well, the TE37s are super lightweight. The wheels I am buying are not much lighter. However, I should see a slight performance boost, despite the increase in wheel diameter, for two reasons.

One, the wheels that are on the car are not stock. For some reason, the sidewalls are larger than they should be. The tires on there now are 215/60/16s. Why did the previous owner put on 60s? I don't know, but it adds to the total wheel diameter and weight.

Two, the wheels and tires both should weigh less. I know the wheel weigh about 18 pounds a piece, a solid 4 pounds less than the stock wheels. On top of that, the tires should also weigh less. Even though they are a little wider, they are significantly lower profile, and therefore I estimate the total mass to be less.

The wheels are supposed to come on the 20th, so I should know in a few days whether the performance went up or down.