Last post on Mar 23, 2013 at 10:55 PM
You are in the Vans & Minivans
What is this discussion about?
Mazda MPV, Nissan Quest, Kia Sedona, Chrysler Town and Country, Honda Odyssey, Toyota Sienna, Van
#1366 of 1887 Re: Chrysler Town and Country Limited (2001) Fuel [willem]
Dec 06, 2005 (12:59 am)
First I think too that my drive style is a problem, but is not. For the test I exchange for one full week MY TC 2001 (Limited) with my freind same TC 2002 (LXI) he say that he make over 340 miles on his car. Result: I drive his car 337 miles with same style of drive that i do on my car. He make on my TC 275 miles. So where can be a problem...? Fuel injector? Tune-up? Bad computer setting...?
On some other forums I see info: that if I try to clear my computer (disconnect the battery) this will resolve my problem. This can be true...?
Thanks for any suggestions, Artur
Dec 06, 2005 (7:45 am)
On my Sienna the gas mileage range is calculated from the lifetime average. If my lifetime average is about 20 mpg and my last few trips were 26 or 27 mpg, the range is still calculated with the 20 mpg, and would only be about 400 miles (21 gallon tank). Resetting the trip computer does not effect this.
I know the VW lifetime average is really a moving average of your last 1,000 or so miles, so if Toyota (or Chrysler) are like this then a long trip may bring up your average.
The whole point of DTE is so that you don't run out of gas - the last thing it wants to do is tell you you can go further than you really can. Since it does no know what you will do next it uses a long term average.
#1368 of 1887 Re: Chrysler Town and Country Limited (2001) Fuel [artur_chicago]
Dec 06, 2005 (11:15 am)
in my opinion, relying on a DTE estimate by a computer to judge how much further you can go with the "estimated" gas remaining based on "estimated" MPG metrics -> it can be problematic.
i prefer the low-tech method.
don't you have some indication of relative amount of fuel remaining, and also have some form of low-fuel warning light?
personally, i've always been successful with my vehicles judging when to fill based on the low-fuel warning light, which comes on conservatively when i have 3-4 gallons of fuel remaining. you really don't want to run out of fuel.
anyway, if i had a DTE or MPG estimator in my vehicle, i wouldn't use them, for the simple reason the short-term numbers are impacted by your short-term driving style, and as far as using or relying on long-term numbers, well, they don't reflect what you have been doing in the short-term.
try this: fill the vehicle, reset the trip odometer, run the vehicle till it's low on fuel, then fill it and divide miles driven into gallons pumped. do this a few times to get a handle on how accurate your vehicle's MPG estimator is if you want... but regardless, don't rely soley on that automation.
#1369 of 1887 Re: VCM vs Non-VCM gas milage [caravan2]
Dec 06, 2005 (2:46 pm)
When I first heard, it was disappointing to me. I still wonder that this new technology worth getting just 2 extra MPG. over time 3 cylinders more worn than other 3
Is the glass half full or half empty? I would say over time three cylinders less worn than the other three.
Also, it is not new technology. Cadillac did this (poorly) in the early 80's I believe. What you get with this technology is about a 10% gain in fuel efficiency for relatively little cost. It is a shame, though, that the deactivated and activated cylinders do not alternate. I guess that would require even more sophisticated noise cancellation technology.
#1370 of 1887 Re: VCM vs Non-VCM gas milage [fljoslin]
Dec 06, 2005 (3:03 pm)
What makes anyone think that 3 cylinders would be less worn? VCM technology doesn't mean the pistons aren't operating; all that happens is the intake valves remain closed for those cylinders so the fuel/air mix is restricted to the other 3 operating cylinders. I can't figure out why this would lead to differential wear in the engine (besides, virtually ALL wear in the engine occurs with engine startup when all the components are cold and all the oil is in the oil pan. VCM or no VCM would have NO effect on startup wear).
#1371 of 1887 not quite right
Dec 07, 2005 (1:25 pm)
If the valves didn't open you would get engine braking on the three inoperative cylinders(similar to a jake-brake on big diesels). They still open and close normally, but no fuel(or very little) is injected into the air that is passing through. The only wear and tear that might occur is on the crankshaft bearings when the power pulses become more uneven due to high torque on firing pistons verses low torque on non firing ones. I would think that would be minimal. The three cylinders without fuel act a bit like the pistons in a compressor, just moving air. Your emissions should be very small with VCM engaged as your cat converter is getting more air to complete combustion.
#1372 of 1887 Re: not quite right [tcp2]
Dec 07, 2005 (2:16 pm)
I got this from wikipedia:
In part, it reads,"It uses a solenoid to unlock the cam followers on one bank from their respective rockers, so the cam follower floats freely while the valve springs keep the valves closed."
Note the part where it says "keep the valves closed."
Honda's VCM technology is an offshoot of their VTEC technology and works by some of the same basic principles.
Here is another write-up on Honda's VCM technology:
#1374 of 1887 Gas mileage for a 2002 Chevy Express Conversion Van?
Dec 07, 2005 (3:52 pm)
I just bought a 2002 high-topper conversion van (Chevy Express).
I had a question about gas mileage.
I've only used one tank so far. Roughly 70% highway (with cruise control on) and the rest city driving.
My results were roughly 10 mph. Ugh! I was hoping for more.
It does have a Wheel Chair Lfit which ads weight.
I've read varoius places on the internet and in discussions where people with the same van/configuration are getting 15 to 18 mpg.
So I'm curious. Is 10 mpg really bad performance for this vehicle?
Anything I can do to improve it?