Thanks for all the good suggestions guys. Now for the responses and a few
more questions. I have the 3.55 rear in an All Wheel Drive, Front and Rear
LSDs.
1. New plugs. I believe it was to a colder plug. What does that do for
carbonization of the back sides of the valves? Checked www.boschusa.com and
they don't list a plug for the 2000 4.7l, maybe that's the reason people are
telling you not to put them in? On the other hand, NGK makes a direct cross
in a platinum. Maybe that's the way to go?
2. Timing. What I've gathered from this and other forums is that the 4.7l
can take more advance than the other models but the timing gets retarded
because of a generic flash update that is common to all 2000 (01?) Dakotas.
The other motors are having more troubles with this than the 4.7l? So if I
can find a chip that advances the timing I'll get better economy but lose a
little bottom end grunt?
3. Cat back exhaust. So far the only product to make a specific claim of
better mileage in thier ads. My concern is it also says 'more power'. In
general you need X gallons of fuel to make X Hp. So if you make more power
one would think you'd burn more gas. In most computer controlled motors
they adjust the air/fuel mixture so if you alter one side of the equastion
by adding more air, won't the computer just compinsate by adding more fuel?
The only other explanation is that the exhaust improves on the efficiency
(sp?) of the motor. Are these systems louder/noisier than stock?
4. Synthetic fluids. I've seen a number of posts regarding this and I
think that going to Mobil 1 is gonna be a given. Ran it in my old vehicle
and loved it. I've seen posts saying not to run synthetic transmission
fluid for one reason or another, something about the different types of
synthetic. You gotta make sure you get the right one or you can cause more
damage then save. How about differential fluid? It seems to me that the
diff fluid in my truck has the consistency of roofing tar. Sometimes I can
drive 5 or 6 miles before it locks up and the RPMs drop to normal,
especially true in cold weather.
5. Thermostat. A number of people have suggested this. I'm really not
sure what this will do for me. I guess it's feasable that a cooler running
motor means cooler cylinders and less likelyhood of ping. But I'm not
having that problem. If I manage to get the timing advanced maybe I will?
Comments are welcome on this one.
6. Snake oil. Read a few posts about fuel line magnets and fuel catalysts
but I really wonder what the deal is. I found a report on the EPA page
about some of the products that were tested and proven to improve mileage
but haven't been able to read the results from the individual test to see
which one made the biggest change.
Thanks again, in advance for all you help guys.
Rich.
"ZeRTified" <zrt800@iname.com> wrote in message
news:k8uvat835g0ma7dtagradbtbj6g4grka6f@4ax.com...
> Hey Guys,
>
> Just found this NG and have found lots of useful info.
>
> I have a request from all the 2000 4.7l 4x4's out there. I'm seeing
> very poor gas mileage. ~13mpg (city(-) and highway(+)) and was
> wondering what can be done to improve on that. I've already installed
> a K&N filter but it's too soon to tell how things are shaping up as
> far as gas consumption goes.
>
> The US EPA states this vehicle should get 13 city and 19 highway for
> an average of 16mpg @ 45/55(?) but on the last trip to the cottage,
> the best I got was 13+, all highway @ 65mph.
>
> In any case, I'm relatively mechanically inclined but don't want to
> spend a fortune, tear down my block and add XXXhp. What I'd like is
> some quick and easy mods that can up my MPGs without sacrificing
> lifespan or reliability.
>
> The things I've been reading about is a plug change and t-stat change.
> Will these simple things add to my fuel economy or are they
> performance mods that'll boost the get-up-and-go, but suck more gas
> out of my wallet?
>
> For the record I'm in Toronto, Ontario and the 13mpg was in U.S.
> gallons. Miles (Kms/~1.6) on the odo / gallons (litres x 3.78)
> pumped. Not overhead computer. (Don't have one)
>
> Any help would be much appreciated.
>
> Thanks in advance.
>
> Rich
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