All Camrys we have owned had the 2.2L gas auto setup. I was getting around 26-28 mpg in the summer always driving 5mph over, 75-80 on the express ways, and having the shift points at about 3000 rpm (including lower gears). Funny thing is, according to the link below, the camry is around 300 pounds lighter, but share a lot of front end parts.
1992-1996 Toyota Camry: Full Review - Consumer Guide Automotive
I think the areo on the camry can be in proved quite a lot vs the 97 Lexus Es300 photos I found on google. The back window looks to be a steeper of an angle and the trunk seems taller. The front end looks to me like it would be harder to push in the wind too.
Funny thing is, according to fueleconomy.gov the average mpg for the camry is better (22) and the lexus is at 19. Only way I was able to get 22mpg in my camry is in winter and not knowing all of my tires were around 25-27psi and driving "normal".