To The Moon: Upping economy in a 2000 Dodge Caravan

[Geocritter]

I had a 1998 3.0 liter Dodge Caravan. Just before I sold it I took a 2000 mile R/T from Houston TX to Iowa pheasant hunting. The Caravan had 280,000 miles on the odometer. I consistently drove between 60-65 and averaged 26mpg. I estimated my mpg by dividing miles driven by gallons purchased, I don’t have a ScanGauge. I’d pulled out the back seats so I could sleep in it, but still carried the weight of my camping and hunting gear as well as my 75lb golden retriever. If memory serves me correctly, I inflated my tires to 45psi. All things considered, I was very pleased with the 26mpg I was getting. The 3.0 liter engine was an excellent engine, gave me no non-maintenance problems, and was still running great when I sold the Caravan at 286,000 miles (wish I could say the same for the AC and AT LOL).
Steve

[101Volts]

The van seems to be going through coolant faster than we'd like so I removed the duct-tape grille block. I might add it again in winter conditions, When it can make more of a difference. We also need to replace brake pads.

Also, Since I reset the SGII to factory defaults I haven't had any wonky tank readings but we also haven't filled the tank up since 2013-September-17 yet.

[Geocritter]

Originally Posted by 101Volts

The van seems to be going through coolant faster than we'd like

If your losing coolant I'd say you have a leak somewhere, your engine has a long hidden metal tube that runs under the intake manifold to the water pump (that's buried in among the cam pulley's), perhaps it's leaking from there when the system pressures up and then stops leaking when you let it cool down. If your running it hot I'd be very very careful, aluminum heads are not very forgiving when they're overheated. They tend to warp and also develop cracks between the sparkplug hole and the exhaust valve. Like I told my late wife and kids, if you're overheating pull over as soon as it's safe and either call me or call a tow truck and tow it home.

Anyhow, good luck with it.

Steve

[Fat Charlie]

Or it's the elbow pipe back to the water pump. Or it's the supply and return to the rear heater... Lots of places to loose coolant in those rigs.

[101Volts]

Whatever the case, We have a "Stop Leak" Additive we might be putting in the van soon prior to filling it up with more coolant.

The SGII was bugging out again at re-fill time; It said some high figure like 1700-1800 gallons used.

[Geocritter]

Be careful about using too much stop leak, it can clog up your cars heater and even effect the radiators cooling capacity (a hard lesson learned). I have had good luck with it though, I even used it to temporarily (for 60,000 miles) fix a cracked head (the exhaust valve seat to spark plug hole crack I mentioned earlier). However, when I finally had to replace the spark plugs the crack opened up again and I couldn't get it to stop leaking after that.
Steve

[101Volts]

Thanks, I didn't add the stop leak but my father did.

There's not much to add now except I found 55 MPH might actually be less efficient on highways than a higher speed in this van? Constant throttle at 55 had lower instant MPG readings than at 63-65, At a TPS between 16-25; 16 is the zero (Not holding down the throttle) point.

Going up some long hills, I think I should stay at 45 instead of 35 (While keeping speed limits in mind as they might decrease) and keep the Instant MPG reading above 10 even though the gauge isn't calibrated; On some smaller inclines I can lose 5 MPH and regain it on the way down. And I have to keep the traffic in mind when doing this. Why is it that so many times I've seen many people tailgate me or be so close to it?

Oh and if I were to take the A/C Clutch Relay out of the fuse box, Would that help economy at all? I also noticed I can make a switch for a fuel injector fuse cutoff switch, And would like to do that.

[MetroMPG]

Instant MPG readings aren't the best way to measure consumption at a given speed - they're notoriously fickle.

Better to drive a stretch of road in both directions, and reset/read the average consumption meter at the same points, at the same speed. Average the results.

I'm willing to bet you a donut your van gets its best economy just after the torque converter locks, like practically every other vehicle out there ( http://ecomodder.com/forum/showthrea...you-15182.html ). Anything beyond that is downhill.

Actually, in some vans and trucks, it's possible you may get best economy just after the top gear engages, but before the lockup point, owing to lower road speed (lower aero drag).

http://ecomodder.com/forum/showthrea...you-15182.html

It might save a little bit, if your A/C comes on automatically (as most do) when you turn on the defrost setting on your climate control.

[101Volts]

I'm wondering where to test the van to see what fuel economy we get from it at given, Constant speeds with the cruise control on; I could go on I-80 but there aren't many flat long stretches of road that I know about within fifteen miles of the house I'm living in as of this post date; Perhaps the best thing to do is just test on I-80, I can still gently pulse to 65 on a down slope and then glide down to 55 on up slopes after the test.

I did say that I got more FE at 55 than 65 before, But would like to repeat it now that the SG2 is working better and I'd like to test it differently.

I also timed the water temperature heat-up time (While driving it) And it took between seven and eleven minutes and about 3.3 miles to get to 175-185 Ferenheit, At about 73 degrees Farenheit. Hopefully we'll get a water heater some time, Not only for winter.

Will the defrost still work if I take the clutch relay out? (Maybe I should find out for myself.) The A/C belt is not in the van and I tried using the system with the relay out, It still blew air but I didn't try the defroster.

[MetroMPG]

Defrost: you'll still get heat blowing on the windshield, but you won't have the dehumidifying effect of the AC. So it'll defrost like any old car without AC used to work.