Written by 
Fuel Economy Tips for Drivers of Petrol Automatics
If you currently own this type of car, and you can’t live without an autobox, I would strongly recommend switching to a diesel automatic as soon as you can. In the past, I have found to my own cost, that with a conventional petrol automatic the odds are stacked against you from the outset. The last petrol automatic I owned, was a Mercedes 190E 2.0 petrol with autobox, it was a petrol guzzler! The official figures stated that it was supposed to return 30mpg, but it was barely giving 25mpg when I first got it. With a thorough service, a few tweaks and a light foot, I could get 32mpg without additives, and a little more on a long run. The bottom line is that economy will ALWAYS be poor with that setup, mainly because with an autobox you don’t normally have the ability to induce engine braking on demand. Those of you old folks who are familiar with automatics, will know that when you take your foot off the go pedal, the revs have a tendency to drop dramatically, stepping on/off throttle is more like push/coast, the big problem is that you’re using petrol ALL of the time! The only option you are left with is a superlight right foot! To summarise this type of car, I am just going to say that it is damn near impossible to escape the following equation: Petrol + Automatic = Piss Poor Economy. If you are stuck with this setup, don’t worry, there are plenty more tips on this site, to help slow the descent of your fuel gauge.
