Irving Renewal

Jdemaris, Thanks for the thoughtful post. I do try for mileage as a hobby (I also have a Geo Metro that routinely gets 50+ mpg) and I do, as you suggest, use the MH as a motorhome, retaining the usual functions. I got the Toy because it is capable of better mileage than most other motorhomes in my price range, and we do quite a little traveling in it. Of course I got it to use, not to resell, so any effect on the resale value is not that important to me. I also like the fact that the cabover is tall enough to use as a bed, unlike many other MH's. The Mobil I is used in the hope of less friction, but also because I know that it creates fewer deposits in the engine and thus helps with longevity. The solar keeps my MH batteries charged and I usually have surplus capacity from them for at least part of the day, as they top off my MH batteries fairly quickly once the sun is up in the morning. Your comments about torque curves and efficiency has me thinking about where the torque peak is for the V6 (RPM). I would like to have a tach. I have heard that the 22RE models can get better mileage than the V6, so that may have been a better choice purely for economy. But I do like the fact that the V6 can climb most hills well, and at nearly my normal cruising speed. I haven't noticed any abnormal wear on my tires yet, but I will keep an eye on them. You are right of course that if I'm eating up tires to gain mileage that my net savings in both money and energy are an illusion. Thanks for the good wishes.

Hi Maineah, Since the truck battery would remain in the truck electrical system, I would think that it would pick up the electrical load when the solar panels weren't producing enough to run the engine. The load on the alt (or the solar panels) would include all accessories that were on, the fuel pump and the ECU, in addition to maintaining the battery. My solar panels add up to around 150 watts (in full sun). The reason I would want this setup to be easily switchable is for such a situation as you describe, where the solar could not maintain the amount of charge necessary for a period of time that would cause the battery to discharge to a level at which it could not maintain all the functions of the truck. I agree that without some creative gathering of parts (junkyard air conditioner compressor clutch) and DIY, the clutch idea could get expensive. I do most all of my own work. Still, for the small gain, it would be way down on my to-do list...

Hello Jdemaris, I have severed the link between the truck charging system and the motorhome electrical system, so the alternator never charges the MH batteries. What I'm looking for is to be able to shut the alternator off (or turn it back on) at will and then tie in the solar panels to the truck electrical and charging system to maintain all the functions of the truck while driving it. This is intended to eliminate the load placed on the engine by the alternator that is caused by the demand for electricity from it by the truck's electrical system. (It wouldn't eliminate the load from the alternator bearings simply due to the fact that it is turning unless, as you suggested I put an electric clutch on the alternator like an a/c compressor has). Clearly this could only be done during the day (no headlights) when the sun is out, but that's when I do almost all of my driving. This type of mod (simply shutting off the alternator) has been discussed on Ecomodder and does produce results I would consider significant. I think that rather than just running down the truck battery I could use my solar panels to keep it charged, since they are there producing electricity anyway. Through some checking I have found that between the fuel pump and the ECU it will take 7 to 10 amps to keep the engine running, and I may be able to produce that with my panels. Taking the load off the alternator will give me more engine capacity to power the MH and I won't have to use as much fuel to turn the alternator under load. Hope this clarifies my earlier posts.

Excellent! Thanks, WME!

Thanks for the info on the cluster, twoblocked. I think I'll make the cluster swap my next project.

The SR-5 panel for the 92 Pickup has the tach in the manual transmission version, and maybe in the automatics too. But it doesn't have one that has the transmission gear selector indicator, probably because the SR-5's with automatic had a floor shifter, while the MH has a column shifter. Too bad, and something I could probably live with anyway. I have heard that, at least for my year and model the tachometer instrument panel is plug-and-play; just plug it in and everything works; tach, trip odometer and everything (except the oil pressure gauge). On the oil gauge you must FIRST change the sending unit on the engine, or it will cook the gauge. The idiot light sending unit is an on-off switch controlled by oil pressure, so it will send full voltage to the gauge, assuming it is a light. THis will cook the gauge, which only needs a signal from the variable resistor that the gauge sender has. This is only what I've heard so it is second hand info at best, but worth checking out. I also don't know if any of this would apply to a more vintage Toy PU. like the pretty little one MontanaChinook uses for his avatar.

Maineah, Thanks for this info on the solar panels as a stand-in for the alternator. I do plan to leave the truck battery in the circuit, and to shut off the alternator through the field coils. The thing that concerns me now is, when I switch the solar panels out and the alternator back into the circuit, you mentioned that the alternator will take off at full tilt, thus overcharging. Will the alternator quickly recognize the full state of charge of the battery and back right down to a trickle, or will it be somehow stuck on full charge? Also, I wish that I could use a more sophisticated scan device like the ScanGauge, with all the info it has and the ease of just plugging it into the OBDII port under the dash. I'd love to have all that info to take my eyes off the road :-) Unfortunately, as you said, the older Toy MH's are not OBDII, but only OBDI. Still, the MPGuino is better than nothing. I am considering a swap in my MH to the later 3.4 Toyota engine, which is OBDII. This would allow me to use a ScanGauge, and it is my understanding that, driven sanely, would get me better mileage. I would be able to climb a somewhat steeper grade without a downshift, and cruise at a lighter throttle position. Many people really love this conversion (a little spendy, though)!

I hope I'm not posting this twice; it seems to have disappeared the first time... Hi MontanaChinook, I think (my opinion only) that engine RPM, throttle position, and gear selection all play into fuel mileage. As you step on the gas, all other things being equal, the engine consumes more fuel. The question with regard to mileage is, how far does that fuel take you down the road? This depends on how far each revolution of the engine takes you, and how much additional gas is run through the engine. The fact that you are using more gas per revolution will hurt your mileage, and the fact that you're in a higher gear will help your mileage. The answer is about which is greater, the gain or the loss. I would think that, using an absurd example, if you drove in first gear all the time you could use very light throttle, thus using little fuel per revolution. But each revolution would not take you very far. I think your mileage would be terrible. Second gear would require more throttle, but you would go farther per revolution. Likewise higher gears mean more throttle and more distance. What we need is some way to tell for sure if we're reaching a breaking point where a higher gear will require so much more throttle that it will hurt mileage more than the higher gear will help it. My MPGuino answers this question for me. A vacuum gauge will only give you one variable; one piece of the equation. I think, without another piece of the equation, it would be harder to figure out.. You may just have to experiment by trying both the third gear scenario and the forth gear scenario under exactly the same conditions, checking the actual mileage for each scenario separately. Unfortunately this will only give you the answer for that specific condition (or set of conditions). This is why I like the feedback from the Guino; it instantly calculates all of this on the fly. I know this is little help for you since you have a carbureted engine, making the MPGuino useless to you, I have always heard that the 22R, as well as the RE, are very tough engines and can handle whatever you throw at them. For this reason I think they can probably handle a heavy foot in a high gear, as long as you don't lug them. You may just want to try using a higher gear more often and see if you notice an increase in mileage or not, and go from there. Hope this helps, and good luck!

Hi again, The MPGuino uses signals from the vss (vehicle speed sensor) wire and an injector signal wire. You can set the Guino readout to vehicle speed and compare it to your speedometer (you can also further correct this if you know what your speedometer error is) and then you can calibrate the Guino to read speed correctly. Calibration instructions are included in the instructions). Then you can calibrate the signal from the injector signal wire to give you a reasonable MPG reading and then further calibrate it as you compare actual accumulated MPG numbers with the MPGuino numbers until you have it calibrated as accurately as you are comfortable with. Once you have these two numbers close, your instantaneous and accumulated MPG numbers will also be close. Mine is very close, based on many thousands of miles of data. The only way you will be able to get an earlier, carbureted rig to use the MPGuino is to have an electronic fuel counter in the fuel line (I think they are available) and to have some sort of electronic speed counter (also available). The calibration range on the Guino should allow this, although I can see it would be a major project. It makes a vacuum gauge look like a good, cheap alternative. The MPGuino is a fairly simple hookup for an electronic fuel injection rig, though, whether it's a V-6 or a 22RE. A vacuum gauge is a good mileage tool, but it only tells you about engine load, not about how far a given amount of fuel will take your rig down the road. The issue is that in a lower gear, the engine works less to move your rig, thus a high vacuum reading. But you don't go very far or very fast. In a higher gear the engine will work harder (thus a lower vacuum reading) but you will go farther with each engine revolution than in a lower gear. The question is, will you gain enough distance to make up for the fact that your engine is using more fuel per revolution than in a lower gear. The MPGuino will answer that question; a vacuum gauge will not. I have found that, in my rig, I will almost always get better actual mileage in the higher gear. I obviously cannot say whether the same will be true in your rig, but I suspect that it will in many cases. I started out with calibration numbers that I found on a chart on line that gave numbers that people had found for various cars and trucks. I started out with numbers for a V-6 Toyota Camry, and then adjusted from there. It is admittedly a trial-and-error process, but as you get closer the error becomes smaller and smaller. I found it to be a fun and interesting challenge, though a little time consuming.

BTW Skydancer, I may be able to give you some advice on installation and calibration, including ball park calibration numbers. If your rig happens to be a 3.0 V-6 with automatic, I may have exact cal numbers for you (or at least very close).

Skydancer, I have had mine for a couple of years now. I went to the sites and one is out of stock, another appears to be in England, and the third seems to have some in stock as of a couple of weeks ago. Here is the link: http://mpguino.wiseman.ee/eng Hope this helps; they are great little gadgets!

Hah! There is that... The trick is to only travel in the same direction that the wind is blowing. Even better if the wind is blowing faster than you're driving.

True enough, Derek up North! And, being a hypermiler I hardly ever use my brakes. But the cool factor is compelling! (Actually I do use my brakes occasionally to make a pit stop, or to pick up junk lying beside the road).