Tire Ratings and Mixing them

[Microman]

Bought this 94 Camry, that had two new tires on the rear. Costco only will put on tires that match the rating in the glove box. Apparently Camry came with "H" rated tires, and the Goodyear "Touring" 90T are not the H rating, so the only thing they could do is sell me 4 tires rated correctly.

Should I just go and buy two more similar to the back ones, and have it aligned and move on. I can get two more like the others for 75 + 6.50 and tx apiece. And then 59 for the alignment.

Will I notice the difference, the car is 14 yrs old , already.

Thanks.

Then I need to clean the COLD "regulator" "valve" just at the Throttle Body, so that when the car is cold it will stay idling.

Thanks.