Does any one know what the difference between the 02 and 03 Dakota 4.7L motors are? The 03 is rated as having better gas mileage and I was just wondering what the difference was?

Thanks,

 

I think that's the gear they changed the gear pattern in the TCM?

 

Lol better on gas that is funny. I have the 03 4.7L and average 12-14 mpg

 

Really? is that all city driving or some highway too? Do you have any mods done? I think the 2003 4.7 4x4 is rated at 13 mpg city, 14 average, and 17 highway. So that would sound about right if that was all city driving.

 

Yes i think you are right just looked and looks like in 02 they were still the 4 speed auto and in 03 they were the 5 speed auto.

I also heard something about different intake manifold and heads but i have not been able to verify it.

 

My dads 01 grand cherokee 4.7 got better mpg than his 04 grand 4.7 gets. same models and tire size.

 

It's the transmission in 03 Dodge unrestricted the 545RFE transmissions in the Dakotas and Durangos. Since 2000 Chrysler for bizarre reasons only produced 545RFE transmissions but they made a lot of them act like 45RFE trannies. If you want to Fastman actually sells a program that will hack your transmission and have it start functioning like it was built. I am going to buy it with my tb from them. I'll tell you how it goes, others find TCM that run the 545RFE program not 45RFE and no one complains about it and I've had some people say they get a bonus 1-2 in the city and for highway hyper milers I've hear someone get 25 mpg (from a 4.7) for 00-02 Dakotas which for us is a huge deal. I have a 3.55 with a 4.7 and I have to really watch my throttle to get 22 mpg.

 

I don’t buy into those kind of claims to get better gas millage most people just think it helps but the proof is never there its usually just a feeling of improvement I’m not saying you get nothing from them just not what is claimed.

Remember for every gain somewhere there is a loss.

 

I never do but when you look at the actual math it is pausible. If you can run 18-1900 rpms and be doing 75 not 65 mph the math makes sense. Hell I could get 22 mpg with my 5.7 with that tranny in an 04 durango, what does that mean my 4.7 can get?

 

Not entirely true there is usually a fine line where you can bump up hp and mpg a little bit. Then after that you gain hp but lose mpg. Having a tranny that shifts better will get better mpg. I added a tuner to my 5.2 and I saw a increase in power and mpg.