Hi Everyone,

I have done some searching about this and have come up with nothing, even though I swear i have seen it somewhere on here.

I am getting 18" Flik Artic Gloss Blacks in the winter, and I was curious....

How much will larger wheels affect my gas mileage and performance?

This is the info about the wheel from the website:
Size: 18x8.5
PCD: 5x100
ET: 35
Weight: 23lbs.

Is there a general rule of thumb about

Here is a picture for the heck of it.

 

if they are heavier than the wheels and tires you are replacing, you are adding to the rotational mass of the drivetrain, and that means slower acceleration, longer braking distance and because of the increase in unsprung weight, you have sloppier cornering.

if the overal diameter of the wheel and tire are greater than the tires that are on it from the factory, then your speedometer and odometer will not give you accurate readings either.

and if you have an 07-08 tc, you have to make sure you put the TPMS sensors on your new tires.

 

The wheels are TPMS compatiable, what are the stock wheel's stat's? beside being 17"s

 

i think they are like 19 pounds, but i don't know the overal diameter of them.

215 is the width of the tire in millimeters, 45 is the percentage of sidewall relative to the width of the tire right? so 45% of 215 mm is 96.75 mm. nearly 10 centimeters. almost 4 inches.

so 17 plus 4 is 21 inche diameter, so 21pi = 65.97 inches.

so calculate the states of the wheels and tires you plan to put on, and see what the difference is and you can estimate the difference between wheels and tires.

 

o dear god...i hate math

 

So putting lighter wheels on give you better acceleration, but what happens when you increase in size?

 

well, bigger wheels usually mean more weight, but you can find some larger wheels that are lighter than the stock wheels, but then again, bigger wheels need bigger tires which means more weight yet again.

also, if the overall wheel and tire diameter is greater than the oem diameter, then your speedometer and odometer will be off and need to be recalibrated.

 

yea, but i've been told that's only if the overall diameter is +/- 0.75" different than stock.

 

I have 19x8.5's with +35 offset all around.

And the car feels heavy as hell, sluggish, slower, and I think
I'm noticing a decrease in MPG as well since I commute
every weeek.

But gaddamn, it looks sexy.

 

You would think it would be one of those things that is hard to notice, like the performance gain of an intake. If you hear it affects you in all thse ways, your mind will begin feeling like its noticeable.

 

nope, rotational mass is very noticible.

 

Agreed.

Even my passengers say, "How come your car feels so heavy?"

 

So with 225/40/18 tires and 18x7.5 wheels weighing 24 lbs each, i'll notce a notcieable difference?

 

bigger wheels = more weight and longer full rotations?

but bigger wheels improve handling.

 

^^Mmmm sorta. Wider wheels maybe, but that has more to do with tires than wheels.

 

also how much pressure you put into the tires.

 

how much do the stock wheels weigh?

 

stock wheels weigh like 19 pounds i think

to find the correct amount of air to put in your stock tires, check the driverside door sill

please note that tire information for nearly all cars is on the driverside door sill.

 

www.1010tires.com has a useful tire size calculator, if you don't like math.

 

correct me if i am wrong but is this correct-

If new diameter is too large, it causes more power to turn the larger diameter(tire) causing a loss of speed (1\4mi for instance)

But, if the wheel and tire diameter are smaller than stock, wouldnt that cause the same scenario due to smaller rotational mass causing less distance to travel per rev?

All that compared to a stock car vs aftermarket replacement.

However, if the vehicle were to increase in performance and have a large boost of speed, would the vehicle then have the advantage of increasing it's wheel and tire diameter slightly to have a substantial increase of top end(1\4 mi for instance) since the stock tires on the new performance upgrade would be compared to smaller wheels at that time?