04TL247

Would you be able to tell the difference between the stock (P235/45/R17) and the new (P245/45R17) Mich Pilot Sport A/S's?

Rubbing, decrease in turn radius etc....????

Or should I stay stock size?

Thank you guys for all the help!!

Tom Champagne

I got em...you'll love them,even in winter(if you get any snow and NO FLATSPOTTING). Just a little taller than the 235's so they look like they fill the wheelwell better.

chill_dog

Yep, should fit, no problem...give a little more cush to your ride, too.

Secret Agent

Mich Pilot Sport or Bridgestone Potenza's?

For Ride..#1

For Handling...#2

TBone2004

a 245 is taller than a 235? which numbers mean what again? 45 is the width and 245 the height? I am asking this question cause on my first car as a teenager it had like 205's and they were old man looking tires....I thought the 245 was a wider tire than the 235? And the 45 is the height. Cause that same old car as a kid was like a 205/75/R14 (give or take) and those were taller and skinnier than what we have as stock.

Someone please clear this up - thanks

chill_dog

245 is the width and 45 is the height. But, the 45 actually represents a percentage - 45% of the width. So 45% of 245 will be taller than 45% of 235...but in this instance, overall tire height will only go up about a third of an inch.

TBone2004

Thanks chill - that makes better sense to me.

6speedv6

The difference in sidewall height from:

235/45 [235mm x 45% = 107.75mm]; to

245/45 [245mm x 45% = 110.25mm] is only

4.5mm [110.25mm - 107.75mm], or

0.177165354330709 inches, which is equal to 1 / 5.6444444 of an inch.

chill_dog

CLICK ME

Looks like 0.3 of an inch to me...

6speedv6

Look again. I clearly state side wall height (which in the picture is 106mm vs. 110mm), not overall tire diameter (which in the picture is 644mm vs. 652mm).

2 times the sidewall height is how larger the rolling diameter of the tire is, in this case 8mm = 1/3 of an inch.

TBone2004

is the .7 mph difference in speed anything to worry about - no impact to electronics etc? (I'm guessing this is stupid question since 100 billion people put non-OEM tires on their car every day) Do I need to change anything else with car - if I go 245 instead of 235?

In reality - is the additional cost worth any noticable advantages to getting the 245? I just want the better tire between 235 and 245.

6speedv6

No. That difference in speed is also affected by air pressure and thread wear.

It's just a matter of choice.

dsc888

This is purely an academic question....but would you notice a drop in gas mileage and slightly less acceleration from the 245s versus the 235s? It seems like you would as the the wider tire would weigh more and more drag from the increased width. But I am sure the in creased width would help with lateral acceleration.

dsc888

6speedv6

the larget tire will also turn less times per driven mile. Weight + drag - less revs/mile = not much of a difference, IF the driving habits stay the same. too complicated and too small to calculate.

chill_dog

Yup, for simply going from 235's to 245's, it's all pointless. It only comes into play if you increase overall height by a lot (245/35/20, say) or increase weight a lot (a set of GFG's which weigh close to 40 lbs each)...both of these having a negative affect on equipment, accelaration, etc. The opposite is also true, although I wouldn't recommend decreasing the overall size of your wheel/tire combo (less than X8 or less than 25" or so tall)...if you want gains, lower your weight...just be careful not to damage the usually more sensitive material.

dsc888

6speedv6 and chill_dog,

Guys, thanks for the answers. Now I will look into getting the 245s. I was always under the impression that going with a slightly larger tire would affect the performance and mileage of the car a good amount. Now it seems it won't and you get better rum protection on top of that.

dsc888

TampaMike

Interesting thread & great info. Although the OEM Michelins are long away from replacement, I am already researching...

I too am interested in sizing up to a 245 45 17. I wouldn't mind a bit more 'cush' and the slightly higher profile. I wonder if the 245's would be less subject the warm up wobble / flatspotting that even my Michelins exhibit, even if briefly and slight? I realize this is somehwhat expected on lower profile tires. An improvment in ride comfort & lower noise would be my goal in future tire replacements (although I am pleased with the OEM Michelins). The ratings on Tire Rack indicate I have several higher rated options in these areas (Avon Tech and Pirelli Neros catch my eye if offered in 245 sizes).

I am curious about the Tire Calibration on the Navi Diagnostics. It is currently set to AUTO. Does this have anything to do with tire size? Would it need to be manually set for non OEM tire size? I may be way off here, but it caught my attention on the Navi.

Of course the tire products and selections will likely change by the time I am eady to ditch the OEMs, and hopefull there will be plenty of long term reviews out here by then.