If you’re shopping for a new Mercedes-Benz E-Class today, the most powerful non-AMG variant you can buy is the twin-turbo V-8-powered E550, which comes in coupe, 4Matic sedan and convertible forms.

In its current guise, the 4.7-liter E550 puts out 402 horsepower and 443 pound-feet of torque, which is enough to get the 4Matic sedan from 0-60 mph in a few ticks over five seconds. The trade-off, however, is fuel economy, and the EPA rates the E550 4Matic at 20 mpg combined, 26 mpg highway and 16b mpg city.

To up its fuel economy numbers, The Car Connection says Mercedes-Benz will kill off the E550 4Matic sedan for the 2015 model year. In its place, we’ll get the new E400 sedan, which will be powered by a twin-turbo 3.0-liter V-6 (derived from the current 3.5-liter V-6) rated in the area of 328 horsepower.

Customers won’t see much of a difference in acceleration compared to the current E550  4Matic model, as Mercedes claims the E400 will make the run from 0-60 mph in 5.3 seconds. Unlike the current E550 sedan, which comes only with 4Matic all-wheel drive, the 2015 E400 sedan will come in both rear-drive and 4Matic forms.

Although the E400 (not to be confused with the current E400 Hybrid) will replace the E550 in the E-Class sedan lineup, the E400 coupe and convertible will likely be sold alongside their E550 brethren. Since any such launch is still 18 months off, there’s still plenty of time for Mercedes-Benz to change its mind.

It’s also too early to talk about pricing or fuel economy, except to say the E400 will be priced above the E350 and will return better fuel economy than the E550. We’ll bring you more details as the new E-Class models are rolled out.