The 92's had a different engine management system. (so I'm told) When you floor it in a 92 500E *EG* the brain box allows slightly less ecofriendly emissions, but allot more power. (certainly feels like more HP even before I knew why) When you do the same on a 93 500E the ridid emission standards are followed throughout. They downrated a few HP but the IRL difference is a bit bigger. I don't think 7HP on 3800 lbs will make much of a difference. I would suspect that the 93 500E actually made 315HP and the 92's made a bit more than 322HP. I have driven both 92 and 93 500E's and there is a difference at WOT. If you go to the Renntech page, you will notice that there are separate tuning packages for the different engines. The 92's are much more tuneable. Same thing applies to the 4.2 M119 V8's. The 92 and early 93 400E's will be quicker at WOT than the late 93's and 94-95 E420's. Being Mercedes they are not going to tell you the newer cars are slower, just like the SL500's of the same years are quicker than the 500E's despite taller gearing AND several hundred extra lbs. (they are not, the E's are quicker) Just like the CLK55 is rated at the same 5.4 secs 0-60 as the E55. I would think (I have not yet driven either) that the weight saving of a few hundred lbs will give the CLK the advantage. It sure did between the CLK430 and the E430!
I hope this helps...Lee