What's the difference between e350 and e450 Mercedes?

What's the difference between e350 and e450 Mercedes?

The four-cylinder E350 earned ratings of 22 mpg city and 31 mpg highway with rear-wheel drive and 22 mpg city and 30 mpg highway with all-wheel drive. The more powerful E450 model is just as efficient with ratings of 23 mpg city and 30 mpg highway.