2003 Dodge Dakota buyer's remorse... now???

what can be done to improve gas mileage on my 4.7L V8?

I don't mean spend a huge amount and then see 1 or 2 mpg.

Does anyone know any secrets?

 

Keep your foot out of it. It's a V8, what do you want from it? What kind of mileage are you getting now, and what's your driving style? I get 12mpg combined in my 5.9 4x4.

 

purchase a tonneau cover. Between my change in air filter and cover, im averaging 5 mpg more then when i first got the truck. I get about 22 mpg, 80% of my time is highway driving.

Its a V6, but making it more aerodynamic is never bad

 

A better flowing exhaust will probably get you 1-2 mpg. It doesn't have to be a high dollar aftermarket either. Take it to your local muffler shop and have them put on a Flowmaster and make an adapter pipe since the Flowmaster will be much smaller than the original. $110 out the door and an immediate 2.7 mpg gain on my 01 QC V/6. Paid for itself real quick and sounds great.

 

what are you smoking? You do know that flowmasters come in pipe diameters up to iirc 5", right? If you buy the right muffler for the job, there's no need for an adapter. It's especially retarded to buy a muffler that's smaller diameter than the OEM exhaust piping, as that just increases backpressure.

And I've NEVER seen an improvement in mileage from adding a muffler.

 

Damn my mistake there horatio! I should have said shorter and not smaller and thus an adapter pipe is needed to make up for the shorter length of the Flowmaster when using the factory pipes. I just assume that anyone posting has some rudimentery knowledge of vehicle systems and how they work and therefore would not put a lesser diameter inlet or outlet muffler in their exhaust system. And also unless the vehicle is an out of tune PIG there is better efficiency in almost ANY engine when back pressure is reduced and thus an improvement in gas mileage usually occurs. The problem in most cases is that people tend to put their foot in it more because they want to hear their new exhaust therefore negating any mileage gains. I know for a FACT that AFTER the Flowmaster was installed on my Dakota the mileage increased 2.7mpg on the highway. 19.2 mpg before 21.9 mpg after at an average speed of 70 mph. In town 16 mpg before and after. Go ahead and call it bull$hit but the highway mileage proves that adding a BETTER muffler increases efficiency and mileage and I think anyone who knows anything about engines in a street driven vehicle will tell you the same.

 

Well my driving style never changes, hard on the gas, easy on the brakes, and like I said, I've never seen an increase in mileage. My Ram didn't have stock exhaust, but I swapped a pair of cherry bombs for a full header-back 2.5" into single 3" with a flowmaster 30 series for no increase, put a Flowmaster 70 series on my Grand Cherokee, and put a flow-pro (knock off that was sitting behind a buddy's garage) on my Dak, none of those have resulted in any measurable gain. Also I put a header, high flow cat, high flow muffler on my Impreza for no gain.

You got a 15% gain in fuel economy by switching mufflers? That's pretty phenominal, and you'll have to understand why people might be skeptical about it. That is a huge increase in economy. With the tornado-type items where people hope to get better fuel economy they tend to drive easier in order to actualize the fuel economy gains, perhaps there's some subconscious activity? Or maybe a switch from winter to summer fuel assisting the findings? Yeah, we all know that backpressure is the enemy, but OEM mufflers, while restrictive, aren't usually THAT restrictive that a 15% gain would be normal. Who knows, maybe your truck is just freakish and that's all there is to it. More power to ya really though. You're getting nearly twice my combined fuel economy for any one of my vehicles. My Dakota now has tubular headers and a high-flowing muffler, and I haven't noticed my miles-per-tank going up, but I'll check it now that my ECU has had a chance to fully reset itself.

And sorry about that last post, didn't mean for it to come off quite so dick-ish.

 

No prob. The factory muffler was the size of a garbage can. It's a 40 series Flow in the stock single exhaust. Results were from one week to the next in the summer 2003 on four lane highways at steady cruise for the most part. I had something to prove to my wife who had a fit and said that I just wanted a loud exhaust. While it does sound sweet, I just wanted some relief at the gas pump! I was never happy with the mileage from the first week I owned it and after a while decided to do something about it. I now run all synthetic fluids in the drivetrain, Autolite platinum plugs and a K&N drop in air filter besides the exhaust and while it's no race truck it sure runs sweet. Another hint I got from the salesman at the dealership is that they do better when run at 70-75 mph. This is where I have acheived best results in mileage with the Dakota. Now the wifes Neon will run 85 mph all day and never deliver any less than 28 mpg. You outta here the fit she throws when I'm doing THAT mileage test!

 

Wow. Crazy. I've got the 5.9 with 3.92 gears, 31" tires and a lot of weight (not me, the truck. I'm still under 200lbs) pushing around, so yeah, 12mpg combined. I'd be darned ecstatic if I ever saw 19mpg and I wasn't going downhill. I seem to get 16-17 at 60mph, 13-14 at 70-75, and horrible above that. In town? ugh, 8-10. My Ram I get 10 @70, 11.5 @ 60, and 8 in town. My 5.0... 6-10 in town, 15-17 on the freeway I think.