Re: MPG and Defending the 3.9L (was: found 3 mpg)

From: Bill Knight (
Date: Tue Apr 27 2004 - 18:09:32 EDT

I agree, I had a 97 Dakota SLT 3.9L automatic, stock tires. Not sure the
gear ratio in rear. When I bought it I ws getting 17 highway. Installed
K&N homebrew, free flowing muffler, 3923 plugs, and homemade tonnau cover
and went to 21 miles per galon on the highway. Now have a 2000 Durango SLT
5.9L automatic, stock tires. Not sure what I started with but did the 3923
plugs indexed, K&N drop in filter and synthetic oil in engine and get 20MPG
highway doing the speed limit with A/C going. Keys to mileage is proper
tune up, proper tire inflation, and easy on the gas peddle.
"Terrible Tom" <> wrote in message
> Zachary Burcham wrote:
> >
> > What has he got on that 5.9L? I have NEVER heard of a 5.9L getting
> > remotely close to 20 mpg. I thought they got consistant 12-15 figures,
> > even in the durango. I have a buddy with a 3/4 ton ram and he's
> > averaging 9.5 mpg. I get 22-25 mpg with my 3.9L dak auto, 2WD with A/T
> > tires and over 160K on the odo at 70 mph. I'm not calling anyone a
> > liar, I've just never heard of a 5.9L getting even close to mid 20s in
> > mpg. One buddy got better gas mileage AFTER doing a 408 with 4.56 rear
> > end. And he only gets 18 mpg.
> >
> Before this turns into a flame war - Keep in mind that MPG numbers vary
> greatly due to many different factors. Gear ratio, tire diameter, tire
> tread design and compounds, engine size, weight, extra crap we haul
> around all the time, and most of all - driving habits. I'm sure if I
> drove my Ram like a little old lady, I could get much better MPG
> figures. I don't like going slower than 75 on the highways - takes too
> long to get places hehehe. Damned cops.
> Anyway - as for the performance of the 3.9L - I got between 13-15 city
> driving in $hitcago, and could easily reach 20-22 highway depending on
> what I was hauling and how fast I was driving. If I recall - I topped
> 22 when I made my first trip out to the BBQ a couple years ago. And
> that was hauling a buncha crap out there with me too.
> The 3.9 engines are sufficent. They never have been powerhouse motors
> but they have unlocked potential. As many on this list have discovered
> there are ways to really squeese out more power from the 3.9 - something
> I'm sorry Chrysler never did was refine these engines they way they
> could have been. The power to weight ratio that can be reached with a
> 3.9 is great!
> As for the 360 - in a Ram - do not expect to see staggering results in
> fuel economy. The Ram is a heavy mother to push around and the 360 does
> a great job of it - but fuel economy is where the compromise is. This
> is nothing to be shocked over. It's always been this way. Brand new
> Ram of the 80s wouldn't see more than 15 MPG tops. MPG went up slightly
> when the engines went Magnum.
> You will see better MPG numbers on AVERAGE in a Dak than in a Ram
> because of the starting point for weight. Ram = heavier than Dak.
> --
> --------------------------------------------------------------
> ***** Countdown to 2004 DML BBQ (83) Days Left! *****
> Terrible Tom -- AIM & Yahoo Name: SilverEightynine

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