What grade of fuel are you using in your XRS.Had any problems with regular 87 ?

91 should be used because of higher compression ratio. You shouldn't use 87, it might sludge your engine in the long run.

are you serious? i'm not going to buy one if I can't put cheap gas in it

It should be fine on 87. Just ask the dealer when you go to look at it.

Compression ratio is a bit higher on the Xrs 11.5 vs 10 on LE 91 should be used to prevent premature ignition at the plugs in the engine