I am thinking about buying a regular cab 1/2 ton (1500)2WD truck and I was wondering if moparts members on here could tell me which engine gives the best fuel economy??? ....the 5.7 Hemi with MDS system or the 4.7 or the 3.7 engine with it's dual overhead cam ??? I am not sure if I want an automatic or 5-speed manual at this point.
Any special year of truck????
Thanks

Get the Hemi.I have a 2wd quad cab,cap on the back,2004 model W/O M.D.S and it gets better mileage than my father-in-laws 2003 Dakota 4wd quad cab with the 4.7. To give you some idea of what to expect,pulling dads' 16" 15 H.P. boat to Wisconsin,driving 60 m.p.h.on the two lanes,and 70 on the interstate,it got 16.98 m.p.g. in 2005 and 17.02 in 2006. On another trip to Michigan for salmon this fall,no boat,it got 21.4 on the 5 hour trip which is about half 2 lane and half 4 lane. WARNING:if you drive agressively you will get much less!Usual around town readings from the console m.p.g. meter says about 14,so keep it rolling and it ain't bad.I have also found that the m.p.g.meter is very close to the miles divided by gallons method if you drive a considerable distance with it. If you use it for a week with lots of warm up cycles and start and stop driving ,it won't be as accurate.

I have a 2004 1500 with the 5.7 hemi. It has a fuel/climate moniter mounted over head. On the highway I have seen it get as high as 21 mpg, but it usually reads high 18 to 19.5. Around town it read 15. I have talked with several other ram hemi owners who say they are stuck in the 13-15 range no matter how or where they drive I dont know if I got a good one or if the moniter is off. I also have a 2005 Dakota 4X4 3.7. It has no torque, no power, and only gets 15.5 to 16 around town. Its my daily driver. I have been on 1 road trip. Cruising at 65 it read 19. The salesman (friend of mine) who sold it to me told me I would be disapointed in the mileage of the Dakota. He was right I was hopeing for at least 18

Thanks for your responces to my question..anyone else???
I have a 1987 Dodge short box 2WD that I use as my shop truck. I installed a 1969 383 magnum and a 4-speed/overdrive and with the thermoquad on it I get 12-13 on the highway...but I am sure that I did much better with the Edelbrock 650 Thunder series that I had on it, so I think it will go back on it. I was thinking about upgrading to a newer truck and getting better gas mileage but I can get 15-17 with the set up on my truck now and I don't think it is cost efective to buy another truck that only is going to give me 2-3 miles per gallon more.

It all really depends on what kind of driving you do the most and how you're using the vehicle.

When one person says "around town" he might mean 45-50mph areas where if you time it just right, you'll never hit a stop light.

Another person can say "around town", and they mean 20mph max repeated stop and go.

One will get far better fuel economy than the other in the same vehicle even though they're both supposedly "around town".

In 20mph max, repeated stop and go driving and lots of idling in between, none of the V8s are going to get anywhere near as good of fuel economy as the V6. The V6 will win every time by a large margin.

From 40-50mph and up, steady cruise with no repeated stopping and no idling for long periods the V8s really shine and do well, often only 1 or 2mph worse than V6s and depending on the driver and conditions, sometimes the V8 will even get better mileage than the V6. It will also have alot of extra power on tap if needed.

So whichever fits the way you drive the best, is going to give you the best balance between economy and power.

The 5.7 is usually fine overall, but when I get caught in stop and go traffic/lots of idling/low speeds I've found it's not much better on gas than a carbureted 360.

If all you're getting with a stock 383 and o/d trans is 12-13, then your carb and distributor likely need some tuning. But you're correct, for you buying a newer truck for mpg will never come close to paying itself off.

Zippy,
Yes..I agree with you that it all depends on a persons driving habbits....I was hoping to hear that people with the 3.7 or the 4.7 were getting 20 + miles per gallon with the full size ram and I thought maybe the Hemi's with the MDS would do better also and in some cases do but I guess not what I was hoping to hear. I had a customer that has a Chevy Silverado with a vortec engine and says he gets 24-26 with his full size truck. He doesn't like the truck other than that reason.
I had a 1997 Dakota 3.9 V-6 with a 5-speed 2WD truck and even at highway cruise for miles the best I could get out of that truck was 19.2 and that was with nothing in the box with the tailage down and traveling at 65 mph. I was hoping for 24-25 MPG with it but I couldn't get it. It had 3:55 gears in it and I even put synthetic oil in the rear and engine but I didn't see a change.
I have also been thinking about an older style Dakota 1991-96 style with a 4cyl and a 5-speed but not easy to find in nice shape.

Seems like I get worse mileage than everybody else. I have an '05 1500 r/c short bed 2wd with the 4.7 and automatic trans. I bought it new and it just turned 46k today. I check my mileage every tank dividing miles travelled by gallons used. My year round average would probably be just over 16 mpg. It seems to struggle to get 16 in the winter and it generally gets around 17 in the summer. I probably got 18+ twice since I've owned it. I live in the country so I don't do alot of 'city' driving but many of my trips are fairly short, less than 15 miles. Trips to town run from 25-60 miles one way. The roads are somewhat hilly and curvy around here and I tend to let it roll on at a pretty good clip. I don't take off fast or hot rod it but I will run 65-70 when I get a chance. It seems to run exceptionally well for a 4.7. I drove a hemi about the time I bought this truck and it sure didn't seem like it had 110 more hp. I've also pulled a trailer with a vehicle on it several times and it pulls it pretty well, even in the hills. However mileage drops to 14. A couple of years ago I installed a Mopar cat back exhaust (Borla), couldn't tell it helped either power or mileage. The spark plugs were burned up at 45k (part time miss), replacing them hasn't made a noticable difference in mileage either.
I'd like to drive one of those 20 mpg hemis or 24 mpg Chevys for a week. I'm not saying they won't do it but I doubt they will get near that much with me behind the wheel and I don't consider myself a hard driver. Maybe the terrain makes that much difference. Maybe it's just me. I never could break 20 mpg in my /6 a-bodies either.
Dallas

You would have to get an 06 and up Ram to get the MDS with the hemi. And it does make a difference if you do lots of highway driving, in the city not so much. Plus you get the wonders of 16 spark plugs and a rats nest of wires running across the intake.

Yea, It seams that fuel mileage is so very different depending on where you live and how your driving habbits are. It all makes sence but when you already have a truck that gets 15-17 on the highway and probabily 10-12 city driving and I don't have any payments on it, I don't see a good reason to change vehicles at this point until I can find a small truck that gets 20 + some miles to the gallon. I was thinking a pre 1996 Dakota with a 4cyl. 5 speed...

2006 hemi 5.7 ram quad cab.
MDS.
city 13.2
best highway 19.2 (ac off) 71 mph. empty
overhead trip computer is way off in city, close on highway.

The smaller motors are on the option sheet to save the buyers money. The HEMI with MDS is the way to go. When you need the power, its ready to deliver. When you want to cruise, it will give better mileage than the other two. Once my overhead mpg readout showed 25.7 while drafting behind a big rig at 50 mph! This was with a 1/2 ton Reg cab 4wd . Keep in mind that these are HEAVY trucks! I now have a 2007 1500 2 wd. It weighs 4980 lbs. My 1974 Dodge Camper 9000 3/4 ton 440/727 weighs LESS at 4780 lbs. All the creature comforts and air bags really pack on the pounds.

below is an old post with more info on the subject of
5.7 vs 5.7MDS vs 4.7 vs 5.9
fuel economy
---------------
At least this month (Jan 2007)
Chrysler has been offering the 5.7V8 with MDS as a
"no cost upgrade"
over the 4.7 on Rams
and pointing out to customers that
the 5.7MDS has better EPA MPG test results by about 1.

{Update, as of April 2010 Chrysler is once again offering the 'no cost upgrade on the 5.7 V8}

When evaluating this, keep in mind that you are comparing a 5.7V8 running on 4
cylinders (and dragging along 4 not being used) at a speed of 55 mph to a
4.7V8 running on eight cylinders also at a speed of 55 mph.

At speeds of 75+ mph the MDS on the 5.7 Ram will not kick in unless you are
going downhill,
or have a wind at your back.
Here at higher speeds the 4.7
might regain an MPG edge.

Even before MDS was introduced on the 5.7V8
the unmodified EPA lab results were showing
that the 5.7 was within 4% of the 4.7 V8
in fuel efficiency.
The actual test results are available online from the EPA at:

http://www.epa.gov/fueleconomy/data.htm

to see the actual results go to this link:

http://www.epa.gov/otaq/tcldata.htm

These are not the 'Window Sticker' numbers,
these databases have the actual city and highway test results down to a tenth
of a mpg. This makes it easier to compare. Since 1985 EPA has applied a
'fudge factor' to these actual results to get the number that you see on the
Window Sticker. This happened because citizens complained the EPA city and
highway numbers were TOO HIGH compared to 'normal driving'. Next year EPA
will apply an even greater 'fudge factor' because citizens are still
complaining that they can't get at 79 mph the MPG that EPA measures at 55 mph.


If you look at the 2003 year numbers
you can compare the Magnum
5.9V8 to the 5.7V8 (without MDS back then)
and to the 4.7V8 and 3.7V6

3.7V6 2wd had 25.4 MPG highway with 45RFE and 3.55 diff
4.7V8 2wd had 24.2 MPG highway with 45RFE and 3.55 diff
5.7V8 2wd had 23.3 MPG highway with 545RFE and 3.55 diff
5.9V8 2wd had 22.0 MPG highway with 47RE and 3.55 diff

Chrysler's official press release on the 5.7 Hemi said that it was 8-12% more
fuel efficient than the 10 year old Magnum 5.9V8 design.
But notice in the above that in the 2003 Ram pickup the 5.7 Hemi was only (23.3/22) 6%
more efficient at highway speed. This may be because the 545 automatic
transmission has more internal friction when in overdrive (where it has two
planetary gearsets turning) compared to the older 47RE auto that only had one
planetary gearset turning.

For comparing the 5.7 with MDS to the 4.7
look at the 2007 year numbers.

4.7V8 2wd had 23.7 MPG highway with 545RFE and 3.55 diff
5.7MDS 2wd had 25.4 MPG highway with 545RFE and 3.55 diff

Adding MDS to the 5.7V8 at a steady 55 mph improved it by
(25.4/23.3) or 9%
This matches what Chrysler said in their press release about MDS on the 5.7V8
where they wrote the most gains were below 60 mph, with maximum gain of 20%
around 45 mph.

{Update: the 2010 Rams are
'more slipperly through the wind'
with the 2wd having a aero Cd of 0.38 and the 4x4 having a Cd of 0.419, so MPG will be slightly better at higher speeds versus 2003-2008 models}

2wd 5.7 Rams will be able to go a little faster in MDS mode and get better MPG
than 4wd Rams because the extra driveline friction and weight of the front
axle loads the engine down more.
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