+1

Rental companies don't take their cars to the dealer for routine service, so chances are the oil has been changed and the standard-issue ERAC lube tech doesn't know (or care) how to reset the oil change interval on several different makes.

Another option is to check for a maintenance sticker. Rental companies don't always use the "Jiffy Lube-style" windshield ones. Check the driver's door jamb for a sticker that says "PM" or "PM due" or something like that. It should indicate the mileage at which servicing is due, then compare to your odo reading.

As a last resort, check the oil itself. If it's anything other than black sludge you should be fine for a couple weeks, then mention the light upon return. If the oil does look in poor condition, you should call them and suggest they send you a replacement before you seize the engine out of no fault of your own.

Hope this helps!