What's the realistic gas mileage on a 3.7L 5sp manual vs a 4.7L auto vs the Hemi with an auto? I assumed the Hemi was much worse, as my TransAm with the 350 LS1 isn't the greatest and weights about 1000lbs less. I got the 3.7L and it just makes the towing limit for a trailer/race car I'd tow occasinally, and I'm second guessing if the Hemi would have been better to get. Don't really want to spend the extra cash for the Hemi in initial cost or gas mileage, but after reading around here for a bit, it doesn't sound like it'd make much of a differrence. Thanks.

 

On the mileage question, you may be right about the differences. Personally I could not stand the thought of somebody running me over when I have to tow. I got the Hemi.

 

Mileage for me in my hemi is running around 15-16.5 (as long as I keep my foot out of it ), that's even with towing a 18 foot boat.

 

Mileage is running about 15 - 16 City and about 22-24 Highway for me. That might change a little after I add my 4.56s. Towing is not an issue for me (especially with the 4.56 gears LS)

 

Had a '02 4.7L, did a trip to FL 15.6mpg at 70mph, and it got 11.2 around town. That was keeping a light foot. Mods were K&N drop in filter, flowmaster single in dual out cat back system, 285/65R17(33") tires, Tonneau cover. The thing would always "gear searching" when hitting the slightest hills. Traded her in on a SXT Magnum. The 3.5LV6 makes more HP (higher rpm) than the 4.7L. 245hp(4.7L)vs 250(3.5L).

 

Here's my take on it. I was looking to buy an 04 reg. cab back in April. I had two friends who had 3.7 5spds. They both told me their trucks wouldn't get out of 12mpg in two and 16 on the highway. And they were not wild drivers. I had to opt for an auto b/c the wife would be driving iit alot too. So i spoke to other people that had the hemi and the 4.7. Seems to me that they all get relatively close gas mileage. And i pulll about 5klbs occasionally on the weekend, so i went for the 4.7 stx pkg. Which was accent stuff and cd player cruise, but no power locks or windows. The comparitive hemi pkg would have cost me $5k extra. The 4.7 auto costs me only 1k more than what i would have paid for the v6 5spd. The 4.7 didn't real powerful when we bought it but at 5k it broke in I guess and it is alot peppier than it was. I didn't need the hemis power, but i needed enough to pulll a trailer around and not be stuck going up a hill w/ geo metro's going around me. I would say if you haven't bought yet and the $$$ isn't an issue get the hemi, but if you are a little tighter it would be well worth getting the 4.7 over the 3.7. The gas mileage is gonna suck on all of them. Good luck, and remember buy what you want, and not what someone else "suggests".

 

04 1500, 4x4, qc, 17" rims, sport pkg, 3.92 rear end, 5 spd auto. With just under 10K, I have been averaging between 14.3 to 14.7 when not towing doing 50/50 driving. Actually, my mileage hasn't decrease much when towing. I am sure the 3.92 and the 4x4 are reducing my mpg, but I felt those features were necessary with a full load in the box and pulling a trailer filled with firewood. The reason for the 4x4 - go into the woods in 2 and 4 will usually get you out unassisted.

 

Think about this.

It takes "X" amount of energy to move "X" pounds down the road. That energy is produced by your engine, by consuming fuel which supplies the energy. If all the engines weighed the same, and the trucks weighed the same and the efficiency of the engines to produce power was the same, then all the engines would get the same mileage.

A v-6 may lug whan heavy reducing its efficiency a bunch and a hemi at idle may be wasting energy, but on the highway at a steady speed, I'd bet each similarly weighted truck would get pretty much the same MPG.

A hemi weighs more than a 6, but may be more efficient. It would be cool to take the weight of the trucks and see how that translate to mileage rather than engine size. Compare quad cab 4x4's to quad cab 4x4's, Singles to singles etc. What difference does a tonneau cover make or other aerodynamic treatments.

A Hemi cost more initially and is the most efficient engine from the factory that I've had. It doesn't lug anytime. Oh by the way, I get better mileage with 89 octane than 87, so my cost per mile is down with 89.

 

MINE IS A REG CAB 04 SHORT BOX HEMI,GAS MILEAGE SUCKED A BIT AT FIRST ON 87 OCTANE BUT NOW AT 12K AND WITH A TONNEAU ITS CONSIDERABLY BETTER AT 19 TO 21 MPG IN SUMMER,A LITTLE LESS WITH EXTENDED WARMUP IN WINTER BUT YOU GOTTA GET WHAT MAKES YOU HAPPY MOPAR IS GIVING US HEMIS AGAIN AFTER A LONG DROUGHT SO IM HAPPY IRREGARDLESS

 

Hi....I'm new to the forums. I have read a lot in the forums concerning HEMI gas mileage...actually a lot of complaining. Just the other day I went 186 miles from home to Colorado Springs and got 27.3 miles per gallon on the trip per the onboard computer. Now this is through winding roads and some city driving. When I am setting the computer from start of fillup to refueling I average 18.4 which is primarily driving just around town. I only have 1053 miles on my '04 HEMI QC SB. My only mod is a 1-in-2-out dual exhaust setup with IMCO muffler. (Sounds great with minimal interior cab resonance) I also live 12 miles from the continental divide at 7,300 feet...so I have approximately 23% less dense air here so, in theory, 23% less air resistance during driving. (I am sure my mileage will drop off when I visit family in the South...below 5k elevation)
For me the HEMI is the choice as I have excellent power/speed, good economy and a V-8 (HEMI) with more horsepower than my 1999 Z-28 had.