Hi Gang - Is just a tune, exhaust ? But what gives the new US spec G55 an almost 40hp bump in power over the (US spec) E55 engines? I know the Euro spec E55 were 500hp stock, and I am not sure on those differences either over the lower rated US sepc cars?

Ed-ju-macate me please.
Yasin

80 mm TB

Huge debate over this for years and years. We have had MANY guys dyno their bone stock cars and have them pull close to 500hp. Car that was tuned before mine at Kleemann in Colorado Springs pulled the highest stock hp numbers they had ever seen. 517hp.

Consensus up to now is that Benz fibbed on the hp numbers to give the S55 and higher classes the appearance of more hp.

If they are using 80mm tb on the G and/or with a simple tweak from AMG tuners, she could pull that easy.

why you at it, the SLR engine is also 113 variant with a SC.

The Marketing Department.

On all 2007 55k engine models, Mercedes starting using a bigger throttle body (80 mm) and also a slight ECU change. This (apparently) happened on 2007+ SL55 and G55 since they were the only 55k models left. However, the difference between the 469 and 493 hp rating between the E55 and 2006 and earlier SL55, S55, CL55 was pure marketing.

Ahhh.. thanks for the replies guys!!