I left Hawaii about three months ago and now live in Germany. I have a 09 Ram 1500 with the 4.7 V8 and 5 speed auto. I had a cat-back dual exhaust with a Borolia muffler installed in Hawaii. Muffler is SS, pipes are steel. The problem is it appears to be running rich. The pipes are black on the inside. Even running at 80mph for over an hour on the autobahn they are still black. Average MPG is 17.5. Should be better. Do I need to flash the ECM? Help please.

 

Hey Bobsled, I just moved yoru post to the section that may be able to help you the best! Good luck and thanks for joining!

 

You have a drop in MPGs because it is colder in germany. Welcome to northern living. Black inside your tail pipes is very normal. Altitude could have to do with it as well. HI would have been very low (better). Germany should be higher.

Is it still cold in Europe? I heard they were having a cold winter. I found my 09 there was two break points. Anything below 25-30 it really tanked. Below 50 and it tanked a little. Above 50 degrees MPGs were basically "normal".

 

17.5MPG is pretty good at 80MPH These trucks are not geared for their best milage at that speed. If you slowed down to 65-70 you would find the sweet spot. If you need to travel at 80MPH, then a gear swap to a numerically lower ratio would help get you back in the engines sweet spot.

 

Thunderbolt, thanks for moving my post.

 

CarGuyOhio, it has been cold, down to -1 degree F. That was the coldest here in Kaiserslautern. The temps have been milder for the last couple of weeks. Up to 50 degrees during the day. Altitude is only 300-400 feet above sea level in my area. The highest point in and around me is 1200 feet above sea level. Bobsled09

 

Oldjeep, 17.5 MPG is really not bad but slowing down to 65-70 on the autobahn where the minimum speed limit is 130 Km (about 80MPH) you can be in the way :-)!

I will live with it, I have no plans to lower the gear ratio, but thanks for the comment. Bobsled09

 

If I take a 500 mile trip (hemi though) at 75-80mph and clear the mileage when I leave 17-18mpg avg is what I see. It will go up 1mpg if I stay below 65. But the local speed limit here is 70mph (which means 79.99mph to most drivers) and like you said if you are going 65 you will be slowing things down.