The last 4.7 Dodge I had was 2003 Dakota AWD with the standard axle, 3.23 or something I think. I used to tow an open car trailer and 3000lb car all over the country with that thing and while it did it fine, mostly in 3rd gear, there is no comparison between that and this 5.7/3.55 truck towing.

I know the newer 4.7 is probbaly better but this whole thing reminds me of the 4th gen f-bosied when they made the switch from the LT1s to the new LS V8s. The LT1s were torque monsters, small ports/runners and cams, but they would really put you back in the seat from 0-30mph and light up the tires at will.

The LS engines 'felt' slower, much slower, but when they started hitting the dragstrips they were nearly a second faster in the 1/4 mile. Granted they were a bit lighter (90lbs or so) but if you drove them both you would swear the LT cars would kill the LS powered cars but in reality that wasnt the case except for the butt-o-meter.

Back to 2010 I will say at times the Hemi/3.55 feels flat off the line and other times it doesnt. The torque management and traction control is super aggressive on these, if it just squeals a tire on takeoff the traction light is flashing and you can feel the power being reduced so I think a lot of the flatness is that and maybe a good tune will help out. FWIW unloaded my old duramax with 600+ft lbs of tourque felt like a much bigger slug then this Hemi, off the line you had to wait for the turbo to spool and lane lane changes with no trailer you had plan well in advance and learn how to roll the throttle - flooring it you could count to 10. But thats typical of turbo diesel.

Maybe instead of dyno or butt racing a gathering at a local 1/8 mile dragstrip would be fun, then the Hemi 3.92 guys and 4.7 guys can lay rightful claim over the lowly 3.21 and 3.55 Hemi guys

 

Hello,

Please reread my post.
You will see we have 4.7s and 5.7s.

We use the 5.7 to tow and haul real heavy items in our construction business.

Our service guys use the 4.7s to get the much better around town and overall mileage.

All trucks have the same rear ends, limited slips.

MDS does not kick in and stay in around town. It is only going to stay on on highway areas with a fairly non hilly terrain.

I have driven all the trucks myself, same driving habits, with no loads except a toolbox which was empty at the time.

The 4.7s get much better around town mileage, and if you drive both on the highway, level ground, cruise control, for at least 50 miles or so, even with MDS, the 5.7s can not get the consistant mileage of a 4.7.

RPMs are so close at highway speeds for both.

We did these tests not using the trip computer, but real time calculations at each fillup.

Which truck is faster? Of course the Hemi.

Which truck gives our fleet the better mileages, the 4.7 by far.

You just cant count on highway all the time, and using the trip computer is only an average.

We use our trucks as works trucks and they are loaded for bear during our seasons, and we use more 4.7s because at the end of the season, we get better mileage.

We will be going back on the road full time in a few weeks, so I will do more testing with me as the common driver for all trucks as I did last time.

Just fyi, my 4.7 on level highway at 62 mph cruise can get 23+, my Hemi gets 20 to 21.

Remember I am speaking fleet use so we look for MPG, we don't just have a truck for speed and show, usually carrying nothing at all.

Again the key phrase is we like the OVERALL mileage of our 4.7s compared to our Hemis. We spend a pile on fuel.

Anywho, We love all our Rams for what they do for us.

 

thats not true at all, in the city here it kicks in once I've reached 50kph or so, and stays on until I hit a hill or need to accellerate again. Not to say that creates awesome milage as I think i average 12mpg in town.

 

My MDS kicks in around town when I hit the cruising speed as well. It is on a lot more than I figured it would be leading me to wonder if I will have four cylinder that wear out before the others.

I am willing to concede that the 4.7 gets better gas mileage but 17-18 mpg around town is just fantastic. I would hang onto those vehicles for dear life. I used to have a 4.7 Jeep and 13 -14 was my summer around town mileage with 22 max on the highway in the summer as well. It was the old 235 hp(2005) model.

Lubrinator:

By the what fuel are you running your trucks on??? 87 or 89 octane???

 

ima just add my 2 cents like everyone else. 5.7 is bigger yes same power... stock wise there close since same transmissions and rears. What makes the hemi a hemi? well you should all know that but its not a true hemi but its what helps, on another thing my buddie had a 2wd 5.7 hemi with sum work done to it and we raced alot and my 4.7 deff kicked his *** alot and i just had the pipes i didnt have the k/n yet. my rear is posi all the time and i am a bit lighter. for hauling the 4.7 does put out and impressive amount. 5.7 is more horses if it was to me i would have the 5.9L and just screw everyone. 5.9l is just a better engine all around the 5.7 hemi was to take the 5.9 over and for "better economy." the 5.7 hemi is the popular engine now and since its the RAM they make alot of aftermarket stuff for it. the New Dakotas are still new so no one has paid much attention of what to do but what nobody really knows is how much u can squeez out the small v8. and what i read earlier on the forums with the new CAM's coming out 390 whp out the 4.7 the new Dakotas gonna be sleepers again just with the 5.9l. so after said and done plus the mpg the 4.7 does sounds good but in the end it all depends on the driver how he drives and what hes going to do. been days where i take it slow and take my time and the dial bearly move... others shes a gas hog cuz my heavy foot. Just rembmer dont judge a books by its cover because it can surpise you what can come out of it.

 

My hemi stays on MDS while passing cars at WOT, I can barely keep it on the road when it shifts into second.

 

I pulled 4 spark plug wires off of mine so it's in MDS full time...and I can still smoke them 4.7's !!!

 

We use 87 90% of the time. If the Hemi trucks tow heavy, we will use 89 or better.

I should have said that all the trucks are 4WD SLT Quad Cabs just for info purposes.

We will be upgrading exhausts and possibly adding CAIs to them. We will try one 4.7 and one Hemi to see if we get a difference before doing all of them. Right now they all have a K&N drop in.

BTW I pay my techs/drivers a bonus on fuel savings each month, so it is in their interest to "granny" the accelerators. This is another reason we get the good mileage, it is hard not to drop the pedal on the trucks though just to see how quick they are.

BTW I am an old fart, so gas mileage is important to my company.

 

I understand that it will kick in "around town". Our around town is stop and go traffic, lights, and some 35MPH stretchs.

That is why we use the 4.7s, with good driving habits we do get 17+around town.

Our Hemis get as yours does 12+.