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whats the best proven upgrade to improve my hemi's fuel economy?

whats the best proven upgrade to improve my hemi's fuel economy?

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whats the best proven upgrade to improve my hemi's fuel economy?

hemiboy hemiboy
New User | Posts: 1 | Joined: 09/08
Posted: 09/29/08
09:54 AM

i just recently bought a 2007 dodge ram 1500 regular cab 5.7 hemi. i love this truck, but it is burning a bit of a hole in my wallet for gas. i'm gonna keep the truck regardless but does anyone know what is probably the best bang for the buck to get to help improve my gas milage? should i get a cold air intake first, or and exhaust, or a programing chip? also my truck came with the 17'' rims on it, im planning on getting atleastthe 20'' rims cause the 17's look small, will this hurt my gas mileage or improve it or not effect it at all? Thanks for any help you can give me  

Edward A. Sanchez Edward A. Sanchez
Guru | Posts: 1908 | Joined: 07/06
Posted: 09/29/08
11:38 AM

Well, the Hemis are not the most fuel-efficient, but they're a lot better than the old 318s and 360s. Honestly, the best advice is to keep your right foot out of it as much as possible. I know it's tempting with all that power, but adjusting your driving habits will probably have as much of an effect as anything else.

I'd recommend doing intake and exhaust together, if you can afford to. There are some programs out now that are tuned specifically to improve fuel economy. Superchips and Hypertech are two popular programmers.

You might also want to consider either a hard or soft tonneau cover for the bed. There's been some debate as to how MUCH of a difference tonneaus make, but even the skeptics admit they do make some difference in fuel consumption.

The 20s will probably increase your unsprung weight per corner a little, as well as decrease your accelerlation, a little. If you're going to go with 20s, get forged rims. Again, a little more expensive, but they're lighter weight, and will have less rotational inertia than heavy cast rims.

Also, if you're in a relatively flat area with not a lot of traffic, use cruise control as much as possible. Hope this helps.  

mwsounds mwsounds
New User | Posts: 15 | Joined: 10/07
Posted: 10/16/08
06:38 AM

I put the K&N intake as well as the Hard tonneau on my 2006 Mega Cab. It has helped a little. With the cruise control set at 70 to 75 on the highway I am getting almost 19 MPG's. Now the city driving I am still at around 12.5 to 13MPG's. I would like to get it better, but the chips are expensive, so I will have to save up. I also shop around for gas. is a great tool to use when looking for the cheapest gas.

God Bless!  

Edward A. Sanchez Edward A. Sanchez
Guru | Posts: 1908 | Joined: 07/06
Posted: 10/16/08
04:44 PM

mw, That's pretty good mileage with what you've done. If you're getting anywhere close to 20 mpg on the highway with a fullsize, I'd say that's pretty good overall.  

steergazer steergazer
New User | Posts: 1 | Joined: 02/11
Posted: 02/27/11
10:26 AM

I have an 07 megacab with the 5.7 hemi non mds engine. first when i bought the truck it did 16-18mpg. since then I have put an intake, magnaflow muffler, superchips tuner and E3 spark plugs all at diferent times and none of it has improved my mileage. I've been told a throttle body spacer will help so that"s the next try. I also didn't put a "cold air" intake on it which I'm also told would help.

I tried a set of 20's on it and the results were brutal! lost 6mpg! So i just bought a good looking set of 17's and called it done.  

06indymegacab 06indymegacab
New User | Posts: 1 | Joined: 01/12
Posted: 01/26/12
06:26 PM

My 06 megacab got about 14 mpg city 19.3 was my best on highway 17" tires had a throtle spacer {araid}and bullydog E-3 programmer other than that it was stock then i changed the tires still 17" but a more aggressive tread they were big-o at's my mileage dropted to 11.7 city and best was 15 highway had to put 70 to 75 lbs air in  them to get that so stay with a less agressive tire i hope this helps