good all season tires?

BlackRoseRacing · Post by **BlackRoseRacing** » Fri Jun 30, 2006 6:40 am

As for the acceleration thing is concerned....
A car with 15's will accelerate faster than a car with 17's...
The reason being that the 17" wheel changes(kinda) the overall final drive of the car.....its like going from a set of 4.10 gears down to 2.73's..
Not exactly but thats the best descrition...
A couple of weeks ago I headed down to the southern tier here in WNY and to maintain 60mph up this one hill when I was using the 17's I had to drop it from 5th to 3rd just to keep up the speed.
The last trip I had the 15's on the car and that same hill I only had to go from 5th to 4th....
As others mentioned, the bigger 17+ wheek on our N/A neons is more for bling than anything. 15&16" wheels are better for al around performance....
Yeah I know the SRT's have 17's on them, but they also have 100hp more than us

Knoxville_R/T · Post by **Knoxville_R/T** » Fri Jun 30, 2006 11:41 am

100 hp more at the wheels then you all do at the crank(rt/acr wise);)

I just had to throw that in. I was excited when I dynoed mine and it put down 247hp and 257tq. That is with only a SRI. But yes, 17's slow your car down.

beelay · Post by **beelay** » Fri Jun 30, 2006 11:59 am

i decided to go with the bfg traction t/a's in 205/55/15 on my stockers because I don't really want to buy steelies for the winter. If it's really bad after a couple of trips up snowboarding i'll order the steelies with winter tires from discountdirect or tirerack. The bfg tires'll come in monday and i'll have them mounted balanced and alighned. Was this a good decision?

Knoxville_R/T · Post by **Knoxville_R/T** » Fri Jun 30, 2006 1:09 pm

YES. Especially since you are not wanting dedicated winter tires. With the 55 series the wheel gap will also be less.

Wisher2 · Post by **Wisher2** » Fri Jun 30, 2006 1:29 pm

Falken ziex 512's FTL

My sister-in-law has them on her car and they are complete garbage.....I dont even understand how they can be called a performance tire....Massive sidewall flex....garbage.......I believe I will only buy BFG's from now on no matter what

kc2005ptgt · Post by **kc2005ptgt** » Fri Jun 30, 2006 2:38 pm

Wisher2 wrote:Falken ziex 512's FTL

My sister-in-law has them on her car and they are complete garbage.....I dont even understand how they can be called a performance tire....Massive sidewall flex....garbage.......I believe I will only buy BFG's from now on no matter what

I have to disagree, but I will do it nicely

I must say that the Falkens were a huge upgrade from my twice as expensive (retail) michelin harmony's. The traction is awesome, I can corner better, faster, and it takes a really big 'clutch pop' to squeal the tires, whereas with the michelins, I was constantly 'squealing' (even when new tread), the tires screamed going around corners fast, and they hydroplaned really easy! These are much better tires, and at 55$ a piece, I love them.

OB · Post by OB » Fri Jun 30, 2006 3:10 pm

BlackRoseRacing wrote:As for the acceleration thing is concerned....
A car with 15's will accelerate faster than a car with 17's...
The reason being that the 17" wheel changes(kinda) the overall final drive of the car.....its like going from a set of 4.10 gears down to 2.73's..
Not exactly but thats the best descrition...
A couple of weeks ago I headed down to the southern tier here in WNY and to maintain 60mph up this one hill when I was using the 17's I had to drop it from 5th to 3rd just to keep up the speed.
The last trip I had the 15's on the car and that same hill I only had to go from 5th to 4th....
As others mentioned, the bigger 17+ wheek on our N/A neons is more for bling than anything. 15&16" wheels are better for al around performance....
Yeah I know the SRT's have 17's on them, but they also have 100hp more than us

Ill have to disagree a bit about the 17s making the car slower. The only things that could make a car accellerate slower is if the OVERALL tire+wheel height was changed to be larger, and if the new wheel+tire combo is HEAVIER. A larger wheel+tires combo that weighs exactly the same as the smaller wheel+tire combo should perform exactly the same. Make sense?

Knoxville_R/T · Post by **Knoxville_R/T** » Fri Jun 30, 2006 4:45 pm

^^yup

Post by **racer12306** » Fri Jun 30, 2006 5:01 pm

orangeblastsxt wrote:
BlackRoseRacing wrote:As for the acceleration thing is concerned....
A car with 15's will accelerate faster than a car with 17's...
The reason being that the 17" wheel changes(kinda) the overall final drive of the car.....its like going from a set of 4.10 gears down to 2.73's..
Not exactly but thats the best descrition...
A couple of weeks ago I headed down to the southern tier here in WNY and to maintain 60mph up this one hill when I was using the 17's I had to drop it from 5th to 3rd just to keep up the speed.
The last trip I had the 15's on the car and that same hill I only had to go from 5th to 4th....
As others mentioned, the bigger 17+ wheek on our N/A neons is more for bling than anything. 15&16" wheels are better for al around performance....
Yeah I know the SRT's have 17's on them, but they also have 100hp more than us
Ill have to disagree a bit about the 17s making the car slower. The only things that could make a car accellerate slower is if the OVERALL tire+wheel height was changed to be larger, and if the new wheel+tire combo is HEAVIER. A larger wheel+tires combo that weighs exactly the same as the smaller wheel+tire combo should perform exactly the same. Make sense?

edited after i thought for a few minutes about what BRR wrote

BRR is right, because larger diameter wheels change the moment of inertia in the tire wheel combo.

Wisher2 · Post by **Wisher2** » Fri Jun 30, 2006 6:34 pm

kc2002acr wrote:
Wisher2 wrote:Falken ziex 512's FTL

My sister-in-law has them on her car and they are complete garbage.....I dont even understand how they can be called a performance tire....Massive sidewall flex....garbage.......I believe I will only buy BFG's from now on no matter what
I have to disagree, but I will do it nicely
I must say that the Falkens were a huge upgrade from my twice as expensive (retail) michelin harmony's. The traction is awesome, I can corner better, faster, and it takes a really big 'clutch pop' to squeal the tires, whereas with the michelins, I was constantly 'squealing' (even when new tread), the tires screamed going around corners fast, and they hydroplaned really easy! These are much better tires, and at 55$ a piece, I love them.

You should try something better like the BFG g-force sports and see what an upgrade it is from the Falkens.......

grambo · Post by **grambo** » Fri Jun 30, 2006 6:49 pm

Dunlop SP Sport FM901...

Wisher2 · Post by **Wisher2** » Fri Jun 30, 2006 7:23 pm

There you go

TomZ · Post by **TomZ** » Fri Jun 30, 2006 8:52 pm

A little more fodder for the 17"+ tire argument: even with the same overall tire/wheel combo diameter, a 15" combination (assuming the same tire type/relative weight), will out handle a 17" combination due to the moment of inerta (as said earlier) and some simple physics to boot. A tire with a "taller" sidewall (even though it flexes more) has less tire vs. wheel weight due to the higher proportion of air as compared to wheel. No wheel I know of weighs as little as air. Watch an autocross. Autox is all about handling. What size wheels do the fastest autoxers run? Unsprung weight is a huge factor in a g-machine. 17"+ wheels are an appearance mod that detracts from performance. I'm not against asthetics, but prefer performance.

FWIW, tirerack does some great, relativly unbiased, heads-up tire comparisons. Search the site, there's some v/g info. Dollar wise and for a daily driver, I like the 512s. All tire choices are some type of compromise, it just depends on what you want out of them.

lilolneon · Post by **lilolneon** » Fri Jun 30, 2006 9:35 pm

Theres more metal/allow to spin aroudn in a 17" than a 15" or 16" It adds more weight to it, but like OB said, if you have a low prof tire that weighs less than the 15" or 16" tire did, and it keeps the same overall diameter/length then it should be about the same right? (i think i just reiterated what OB said

)

OB · Post by OB » Sat Jul 01, 2006 12:30 am

inertia is based on wieght, so as long as the 17 is lighter than the 15 and the overall combo is lighter and same overall height, they should perform exactly the same. The car cannot tell where the weight is, so inertia shouldnt come into play as long as the wheel is well balanced and light.

And autox dudes likely use 15's because theyre generally lighter than larger wheels, but mainly because they are much cheaper, as are the tires mounted to them. Most types of grassroots racing is based around budget to performance ratio, so the 15s are simply more cost effective and get the job done handling wise. my thoughts, at least.

TomZ · Post by **TomZ** » Sat Jul 01, 2006 9:23 am

http://science.kennesaw.edu/physics/P08_rolling.pdf

I'll paraphrase: The further from the axis (wheel center in this case) the weight is, the higher the moment of inerta (MOA). Higher MOA equals less acceleration. Metal weighs more than air or rubber. Even if the tires/wheel combos weigh exactly the same, overall, the combo with the lower MOA will accelerate and change direction faster. With the same overall heights the larger rim combo will have a higher MOA.

The difference between the price for a 15" vs. 17" or larger tire/wheel combo, especially at regional and national levels, is definetly not a factor. Those boys (and girls), play to win, and spend lots of money to do so. If 17"s were the hot ticket, they'd sport 'em.

Physics rocks!

Post by **racer12306** » Sat Jul 01, 2006 4:57 pm

ding, ding, ding, we have a winner.

OB · Post by OB » Sat Jul 01, 2006 9:34 pm

that makes sense, i suppose i didnt think of it that way. well put, point taken

03blackrt · Post by **03blackrt** » Sat Jul 01, 2006 10:26 pm

TomZ is very correct. Physics never lies (well, in the macro-world where newtonian mechanics apply)

here is a technical explanation of rotational acceleration

M=Ia , where M is the moment applied to a body, I= the moment of inertia of the body, and a= the angular acceleration of the body

therefore, if the moment applied remains constant (this is the power coming from the axle and turning the wheel) and I (the moment of inertia of the wheel) decreases, a (the angualr acceleration of the wheel) will increase.

detrmaning the MoI of a wheel and tire comb is a little more involved, but it does decrease as descibed above.

edit: back on topic, my dad has BFG Traction T/A's and they are great all season tires.