DougandhisC280

bigger? or wider? By bigger I'm guessing they meant taller sidewall. That gives worse hadling. Gas mileage will hardly be affected and as long as you get decent tires hydroplaining won't be a problem.

tpliquid

giong from 15 to 18's i notice power loss due to heavier wheels. there for when i want to accelerate i need to use ore gas so then my gas milage goes down. also widder tires gives more resistance. so therefore u need to use more gas

narci

coming from where it snows (i can say the same for rain) the thinner the tire the better the traction.

wider tires are only good if it's dry. as well..wider tires will make your car track funny bevause of the grooves of the roads.

DougandhisC280

Tp, that's crazy. Even if the wheels are five pounds heavier the low profile tire will weigh less to help even it out. I can assure all of you there will be hardly any difference in gas mileage by changing out wheels and tires.

merclover

tp's right...
if you compare two tires, one say 195 and the other 255, the smallest tire will have less surface area in contact with the ground than the 255, therefore the friction experienced on the 255 tires wil be greater therefore needing more driving force to accelerate and/or keep speeds constant, plus added that this change in size is applied to all four wheels so the force which friction can exert can be significantly bigger in comparison, so the car will suck more gas than before.
about the hydroplanning, only the clumsiest of drivers would need to be concerned about that

DougandhisC280

I understand if you are comparing 195 and 255, that's a huge difference. But if you went from lets say a 195/65/15 to a 205/60/15 there would not be a significant difference. My 225/40/18 are the same width as my old 205/55/16's. Therefore I maintain gas mileage and traction and what not.

henry47

yeah sometimes when I have a big dinner and I take a drive home, I notice that the extra weight in my stomach dramatically slows down my car. It seems as if I was trailing a boat or something. Does this have to do with larger surface area too?:p

Rincewind

my car is always slow cuz its full of mad chicks

DougandhisC280

I'd get rid of those mad chicks and get some happy chicks.

Rincewind

scorchie

Going from a 15x6" rim to a 18x8.5" rim is about 15 pounds heavier... but the gas mileage increase is due to increased rolling resistance on the bigger tires (195 v. 255 as pointed out elsewhere).

Also, how are your 225/40R18 the same width as your 205/55R16? Using an example tire, like the Bridgestone S-03, the 225 is an 8.3" tread width, and the 205 is a 7.6" tread width... so the newer tire is 10% wider! That's significant. If you don't think 10% is significant, try moving someplace with 10% sales tax.

Oh yeah, did you get your wheels from Tirerack? If so, I recommend replacing the lugs with something real.

-s-

DougandhisC280

Nope, Eurotech. I am using the factory lugs since they are factory rims. Well lets put it this way. I have been recording my gas mileage with every single tank. And none of that "miles per tank" stuff. After changing out my wheels and tires I have seen absolutely no difference. Maybe I'm proving physics wrong here but that is my personal experience. The whole reason this question started was because someone was worried about changing out rims and tires due to loss of gas mileage. I'm just assuring them that it won't make a big enough difference to worry about. And by the way, I measured the tread on both the tires while off the car and completely deflated. 205/55/16 = 8.0, and 225/40/18 = 8.2. Not all tires are perfect or the same but that's what my measurements were.

DougandhisC280

Whose got a 15 by 6 inch rim??? Mine were 15 by 7 stock.

scorchie

My 190E has 15x5.5"!!

I was asking about the lugs because so far I've broken 12 lugs from Tirerack in about one year. They break in twos or threes, so something to watch for. These are only the cone seat lugs, the ones I got from Tirerack for Carlssons (same as AMGs) haven't broken.

-s-

DougandhisC280

15 by 5.5??? My 190 comes with 15 by 6.5. What's the deal with your skinny wheels? I never had a problem with tirerack lugs before. I had them on my old wheels. They did tarnish and rust pretty easily which didn't look very nice but they did the job.

scorchie

I think they put the fatter wheels on the cars they ship to Alabama.

-s-

henry47

damn scorchie, 15x5.5, wtf are you sure your car isn't a civic?

Jano

If any of us could afford a Benz, gas consumption shouldn't be a major concern. If the increase in gas cost is due to bigger wheels and tires in several or tens of dollars per month, maybe an electric hybrid car might be in the cards. But since this thread is about bigger wheels and tires, gas consumption and cost I suppose should be talked about.

DougandhisC280

Damn Straight! Yeehaww!

scorchie

Yeah, it's a 190E Civic.

That wheel is ET49, too. No wonder people have problems when they put ET35 on their 124/201s.

-s-

DougandhisC280

I put ET 35 on my 190 with no problems at all.

scorchie

Yeah, but you could have problems with ET35. We know you just aren't very agressive with tire sizes and lowering...

-s-

DougandhisC280

What's that supposed to mean?

scorchie

Man Doug, you think that there's some hidden meaning in everything I post! I don't insinuate other than what's there. If you are inferring something else, why don't you tell us what it is?

Or, if you just don't know what aggressive means in this context, I apologize. It means your car has skinny tires. And sits high. (Mine sits high too, but I don't run skinny tires.)

Here's a pointer to Merriam-Webster to highlight the meaning of "aggressive". See point #4.

http://www.m-w.com/cgi-bin/dictionary?va=aggressive

By the same meaning... you ARE aggressive when it comes to driving your post count higher. Even if it's by always asking "What's that mean?"

-s-

DougandhisC280

But...What's THAT mean?