In a rut

[endurance]

I joined here and started hypermiling and doing a few basic ecomods last fall. By December I had three tanks in a row over 41mpg, and while I knew it couldn't last all winter, now I'm stuck in winter mpgs. I'm now consistently around 37mpg and can't for the life of me get back over 40mpg.

There are a few things that have changed, some within my control, some less so. First, last year's summer tires were completely shot and when I had my snow tires mounted, they were binned. So this spring I had to buy new rubber, which means really deep tread. I went with a LRR Continental (can't name it off hand, but 50psi sidewall rating) that was a bit of a compromise since we still get snow into May. Also, it's still pretty cool around here with morning lows hovering in the 30s-low 40s. While the car is garaged at about 50-55F, obviously cooler temps have some impact on performance and warm up times. Finally, I've been lazy and haven't been pushing my hypermiling to the limits. While I still do my 8.5 mile gravity drop with the engine off most of the time, I am more prone to re-start when traffic comes up behind me on the flatter/slower sections. I'm also struggling to get up early enough to beat the rush, so I have more traffic to contend with. To some degree, I think I've lost some of my touch.

Any suggestions for getting back in the game? Just looking for a little inspiration. I still want to break 45mpg this summer, but I'm not sure if/how that's going to happen.

[Piwoslaw]

Originally Posted by endurance

To some degree, I think I've lost some of my touch.

Endurance, don't lose sleep over this. There are better and worse times, sometimes you get tailwinds in both directions, but sometimes life throws sh*t in your face. Sometimes you have to get a rest and start over. If you have a bad tank, or a bad month, then keep trying. It's really nice when you get a good tank again after a few crappy ones. We're all keeping our fingers crossed for you, but we won't ban you if your average goes down for a few tanks.

Aeromods always help (duh), see how much more you can improve. The new LRR's deep tread will wear down. The weather will improve. Just don't give up!

[user removed]

I went through that phase in 2008, particularly in the summer, with my Insight and VX. Since then I have sold both vehicles and bought my Altima Coupe and a couple of motorcycles.

Now I am selling the first bike so I will have the 06 Rebel and the 71 CB350. In the whole process my average mileage has remained basically the same, close to 60 MPG. This winter it got depressing when the weather prevented me from riding the bikes and I was using about 54 gallons of fuel in the Altima per month. This last month I have not emptied the Altima tank yet from the beginning of April. The Rebel is 5 cents a mile and the CB is about 6, while the Altima is about 12.

regards
Mech

[BHarvey]

I too seem to be in a rut, but it's more due to me changing jobs so my fuel economy is taking a hit, but I am using much less fuel because I now only drive 6 miles to work.

Still staying in the 38 range with the car but it's very difficult.

The bike will help with this on nice days since it easily can get 50+.

[endurance]

Thanks for the encouragement. This tank is looking a little better, might even break 39 with any luck in the next few days. The SGII tank mpg is never dead on because I EOC a lot and the shut down/start up time screws up the averages, but I crossed over half tank at around 285 miles, which usually means 39mpg. Today's traffic was a bit of a cluster (Wednesday's always are because nobody is telecommuting and it's a core day for my work), but I still managed 53mpg on the way in. Lately I've managed to get 31-32 on the way home (up the hill), so as long as I can keep it up for another couple of days, with my weekend plans it should be the best tank of the spring.

Next weekend I have a long trip to the western slope (read: one long climb, one short climb and massive glides). If that doesn't get me over 40, I'm taking a belt sander to the new tires.

[bestclimb]

I have gone and am going through this too. changed jobs and have a highway commute with rush hour (that will be changing again soon, same commute only once every 2 weeks).

Realize that with fuel prices the way they are, folks are a little more tolerant of slower vehicles. A number of days I have used less than a gallon on the 50 mile drive, some days I have a hard time breaking 40mpg, do the best you can with whatcha got.

in the mountains and at altitude it still gets cold at night, keep using the block heater an hour before departing.

[busypaws]

Put the kill switch on the fuel injectors. It doesn't kill the SG/speedo/odo so all the gliding counts against your average.

[endurance]

Well, this tank, despite a lot of stop and go on my morning commutes finally got over 38, 38.85mpg to be exact. I'd call that a solid tank and it brings my lifetime average (since joining the site) back over 38mpg, which is really what got my panties in a wad.

As for the kill switch, I tried putting a crankshaft sensor kill switch in, but it doesn't work (almost stalls it, but not quite). I had to pay $10 for three days to access the Acura manual to get the wiring diagram and I'm not exactly eager to pay again to get the fuel injection diagram. Besides, the SGII goes off for longer on restart than on shut down, so I don't see it completely fixing the problem, only fixing half of it.

[Piwoslaw]

Originally Posted by endurance

As for the kill switch, I tried putting a crankshaft sensor kill switch in, but it doesn't work (almost stalls it, but not quite).

Did you just press the switch, or press and hold? I use the crankshaft position sensor to kill my engine and I have to hold it for something like 1-2 seconds else it coughs and revs up again. If I hold it for even longer then the ECU throws a 'Low Oil Pressure' code.
Another option may be the camshaft position sensor, though in my case it wouldn't kill the engine (not even cough), it would only prevent it from starting. In many cars those two sensors (crank- and camshaft) are syncronised at start-up so the engine can keep going if the signal from one of them is lost. Killing both at the same time should stop the engine.

[endurance]

Originally Posted by Piwoslaw

Did you just press the switch, or press and hold? I use the crankshaft position sensor to kill my engine and I have to hold it for something like 1-2 seconds else it coughs and revs up again. If I hold it for even longer then the ECU throws a 'Low Oil Pressure' code.
Another option may be the camshaft position sensor, though in my case it wouldn't kill the engine (not even cough), it would only prevent it from starting. In many cars those two sensors (crank- and camshaft) are syncronised at start-up so the engine can keep going if the signal from one of them is lost. Killing both at the same time should stop the engine.

I've tried pressing quickly, I've tried holding it. It almost stalls either way, but even if you hold it in, it resumes idle. It's a hard car to kill. I routinely turn it off with the key and if I don't wait long enough, it just restarts. If I'm going to try again it's going to be with the PGM-EFI circuit.

It doesn't really bother me that my SGII tank mileage is off since it's only my calculation at the pump that matters. Actually, even that doesn't matter as much as the fact that I'm now filling up once every 10-13 days where before it was once every 7-8 days. Hypermiling and telecommuting have saved me around 100 gallons over the last six months and that is its own reward.

She's pushing 138,000 miles and still runs like a champ, so as much as I'd like to replace 'er with something that capable of 50+mpg, the cost/benefit analysis at this point is saying I should drive it until the wheels fall off. With the miles on it, the condition (door dings and paint chips), the trade in/sale price would be lousy. Besides, it's only been in the last year or two that cheap 40mpg non-hybrids hit the market (Fiesta, Cruze, Yaris, VW TDIs), so I might adjust my replacement timeline until I can pick up a newer generation used hypermiler car for under $10k (2013? 2014?). Given the depreciation rate of economy cars and the price point they're entering the market, I might not have to wait that long.