I found a great deal on two almost-new (used 1 season) Hankook Icebear studless snow tires, but they're 245/45/18. Front tires on our cars are 245/40/18. I used this incredible wheel & tire size calculator & comparison sheet:

http://www.bigcustomwheels.com/info_specs.jsp

It states the following things will be different by running a 45 AR instead of 40: When speedometer reads 60mph (96.6km/h) actual speed will be 62.2mph (100.1km/h): 3.7% faster. Will fill out the wheelwell by extra 12 mm. Acceptable for most cars.

So will this be alright? Also, this calculator is fantastic for finding out the theoretical results of a new tire combination.

What has your experience been with running mixed sets of winter tires? (i.e. two almost-new Icebears on the front, two new Blizzaks or new Icebears on the rear) I would think that since winter, for me, will not be ANY 'spirited driving', that it should be okay. I've also heard great things about the Icebears, and since winter tires are normally $200+ EACH, this is a fantastic deal.

I wouldn't do it. Our tires run large up front as is. Adding another almost 4% will have you slamming the top of the tire onto your wheelwell everytime you are in a turn and hit a dip. I say don't do it and consider it a horrible recommendation from that site.

speedometer reads off the rear right. just drive in raised setting should clear no prob.

speedo reads front

i wouldn't either... your wheel can possibly touch the fender when turning, Which will evetually seperate the fender from the front bumper, also causing the clip between the two to vanish on the road.....TRUST ME!!!!!

Okay, passing on the deal. Thanks guys!

Side note... is there any way to fool the left (driver's side) low-beam headlight into raising up a bit more? Service advisor told me it reads off a sensor on the lower control arm. Apparently the screw that can adjust the vertical alightment is busted. Isn't there any other way to raise it a bit? Sometimes it's so low that I can't even see at night

here's my 2 cents --

i don't think you'll see very much difference re rubbing in the front (unless your car is hella slammed, but then you wouldn't be driving it in the snow, right?), but you may mess with the esp/traction control. i know on my infiniti (still saving up for that w220 s65. sigh) that if i run tires that are a bit off (225/50/17 rear 235/40/18 front, which is also around 3-4%, if i remember from the last time i used a tire calculator), the traction control will pull power when i'm accelerating.

Glad you passed on the set.

Our concern was not with how low the car would be set. It was with the front tires only. As you turn the wheel, you expose the entire top of the tire to the fender. If you get wider tires or bring that tire top out (more agressive) at all, it will tend to rub the top of the fender lip when you ar turning and hit a dip. PERIOD.

As far as ESP, etc. yes going larger makes the system overreact since now the triggers are hit sooner. i see it most with cars on 20s and accelerating in turns. My personal rule is to stay at under 3% from OEM. I am now at -0.5% Fronts and +1% rears.