I took my E320 on the highway a few nights ago and went upto 220 km/h. At that point I felt like the engine backed off a bit and I could not accellerate past 220 km/h. I also felt like there was something 'limiting' the engine from reving any higher. Is 220 km/h the limit that's imposed on the E320? I always thought it was 250 km/h??