Dieter; The first thing to keep in mind about your friend's V10 and your 331 Hemi is that his V10 has electronic fuel injection and electronic ignition. On the same engine the difference in fuel economy between an EFI setup and a regular carb setup, when they are both operating correctly, can be as much as twenty percent. With dual quad carburetors the gap in fuel consumption would be even worse. I think that this is the main reason you are getting the same gas milage even though your vehicle is considerably lighter. With your dual quad setup, depending on how rich they are running, and how lead footed you are with the throttle, will make a big difference. If the point ignition isn't running correctly that will also make a difference in power and gas milage. Another factor that will make a difference is how many cubic feet per minute of gas-air mixture your current carbs are designed to deliver into the manifold. Changing the tires won't make that much difference in gas milage but keeping them properly inflated will, just from the reduction in rolling resistance. Other then a tune up you would have to undertake some changes to the fuel system or the engine to make a real difference. If you swapped your curent pair of carburetors with some smaller ones it will help. If you wanted to increase the compression ratio of the engine that would also help. Other then that you may consider going back to the standard four barrel intake and carburetor. The best option would be to go back to the standard carburetor and increase the compression, then you can get more power from a lesser amount of gas. Best Regards Arran Foster 1954 Imperial Newport Needing A Left Side Taillight Bezel and other trim parts. ----- Original Message ----- From: <Dietz800@xxxxxxx> To: <mailing-list@xxxxxxxxxxxxxxxx> Sent: Friday, January 18, 2002 6:26 PM Subject: IML: 8 mpg > Just curious ---- A friend of mine owns a 35 ft motorhome with a V 10 triton > engine and weights at least 18000 LBS makes 8 miles per gallon. Me with my > 55- 331 cid Newport 2- 4 barrel carburetor weighing around 5000 LBS making 8 > mpg also ---if I am on a turnpike. I am sure some of you with the 413 and 440 > engines with a single 4 barrel carb. are experiencing the same thirsty > powerplants. Will new steelbelt tires improve gas mileage, still have the > old H 78x 15 4 ply Remington Cushion Air tires. Any thoughts on this . I > would appreciate very much.. Sincerely Dieter in Pa 55 Newport > >