I have a 96 Sl 500 that runs great but gets lousy mileage. I don't drive it like an economy car but I mostly stay within the speed limit. Most of my driving is local where 25 to 50 mph would be normal. Infrequently I'm on the hwy at 75. I have owned the car for 7 years, I have never gotten 20 mpg. I recently replaced the air filters, although they are lots of years old and probably 18,000 miles. Second replace. I have purchased premium and regular fuel. Perfomance and mileage don't seem to differ. Recently got new plugs. Car is quicker but mileage on last tank was 16. This is a 5 sp automatic with 4 valves per and variable valve timing. Everything works. IS ANYONE GETTING BETTER ECONOMY AND HOW> I can live with this but I'm not happy. I have gotten 19 on 1 tank over the years.

 

specs 14 city, 21 highway, 17 combined. hwy mileage is figured between 55 and 60 and it's no fun getting good mileage. it can really help if you only go down hill.

 

On my 97 SL500 I struggled to get 19 mph ever that took coasting a lot. normal was 16 -17 MPG.
I traded for a 04 SL55 AMG and it runs about the same in town. I got a hight of 22.2 on a tank during a long road trip, that tank was exclusivlly 70 -80 Mph speed on Superslab though.
One burst of the supercharger, and you drop into the 14 MPG range though.

Sounds to me that your normal, you just got used to the performance and take it for granted.

FOG

 

Every time I hit the throttle on my 500 hp SL55 AMG. I yell yeah!! cut more trees, nuke the wales MPG be damned. If I wanted a Preass I'd have bought one.

FOG

 

I didn't say I didn't like to be slammed back into the seat and hear the pipes roar, I was just hoping for a little better mileage. The price of gas is dropping a little (is this an election year) and because it holds 20 gallons, I feel unhappy less often. Don't think a Prius is in my future, I miss the V8 when I drive any other car with a V6. My wife says I'm living in the 50's anyway. They all were V8's. Thanks to all.