So which 2 wheels on the car should be the grippiest
 

Ok heres the thing, I have 2 bald tires, and 2 tires that have like 40 - 50% tread left on them, I went to the dealer to get them rotated along with just a general fix'er up (Oil, Tranny Flush, Rear Differential fluid change etc ..) and when they rotated the tires they put the bald ones in the front, and the ones with some tread left on the back. Now I went and ordered some new Tires (S03 Pole Positions), but where should I put the 2 new tires, and the 2 with 30 - 50% tread left??? I thought you would want the grippier tires on the front but then why would the dealership put my bald tires on the front????

So basically, where do I put the new tires

Order 2 more tires - and rotate them more often this time.

Otherwise, put the old ones on the back to finish them off quickly and get two more new ones.

+1
You really want to risk an accident to save $250??

here is what you do...

2 new up front, 2 1/2 back, go to drift event, come back get new tires XD....

Your Tires.

Are What Keep You.

Planted On The Ground.

They Are What Stop You.

They Are What Keep You In A Straight Line.

Do Not.

I Repeat.

Do Not Skimp On Tires.

For a street car, you always want the tires with more tread on the back, so that the rear of the car has greater resistance to hydroplaning if there's water on the road, especially in a turn. If the front hydroplanes in a turn, the car goes straight. If the rear hydroplanes in a turn, you'll be backward before you know what happened.

If the car tends to wear front tires faster (FWD), then you need to buy them in complete sets and rotate frequently enough to keep all the wear even.

If the car tends to wear rear tires faster, just keep rotating them so the ones with the most tread are on the back. They'll all wear out together, and you start over with a fresh set.

....

+1

Let's hope your bald tires you're replacing were S03s as well, mixing different brands/construction tires on the car is ill-advised and potentially dangerous. Think slip angles and grip for starters.

Tires all the same, fairly even wear, and you've got predictable handling esp when the 8 is so well balanced. If one end lets go chances are the other will too, and you'll feel and know it.

Mix tires, two alike front, two alike rear, and all bets are off. Whos on 1st, and what happens next are unknowns, until it happens. bad, bad, bad idea.

Spend another $250 on 2 more deal tires (S03s) and rotate next time. If $250 is a stretch, better sell the car anyway.

You want more grip in the back or you get over steer. Referring to street use.


Also, think about this next time you want to use bad tires. your entire contact patch with the road for all 4 tires can fit on a single 8 1/2 x 11 sheet of paper. this number includes the area of the gaps from your tread design, so its really less than a sheet of paper. So that small of an area keeps you on the road and alive, i wouldn't try to save a few bucks on bad tires.