Help me see 55 mpg!

[Loren]

Originally Posted by 50MPGDream

woah! did you get fuel at the same pump you went to last time you filled up? my SGII has never been that far off. what correction % are you at?

I did fill at the same pump. I've just finally wrapped my head around the correction thing, and I'm sure it was screwed up. I'm experimenting with a 6% correction factor right now.

My correction may be more than normal because I'm running tires that are about 1% shorter. I have to correct my calculated mileage for that, too.

I'm trying to get it to where the ScanGauge reads slightly LESS than actual MPG. I would prefer it to be off in that direction.

[Sodium Duck]

See? =] wacka wacka wacka!

[Loren]

/thread

[Bob_VT]

Great try Loren. It appears as if we have a goal.

[Loren]

It's funny... when I autocross, I have a big bag of excuses that I'll pull out as necessary. But, I don't feel the need to make excuses here. I guess it's because this is so much more "scientific" than autocross. It is what it is.

That said, I will admit that I *did* lean on the throttle too much during a good portion of this run, and wasn't as focused on it as I should have been. But, I have an excuse! Mainly, it comes down to traffic on about half the route (the faster parts, where economy was already taking a hit). I was leading, Jeff was behind me in his Sentra, and he usually kept a good distance, but as mentioned, he was P&G in an extreme fashion. I tended to stay around 50-55, where he would pulse to 70 and charge up behind me, not starting his glide until he was a good 20 feet from my bumper. Not a problem, but it caused me to always have to check my mirror to see where he was when I wanted to start a glide.

Couple that with some impatient (yet dumb enough to NOT take advantage of many opportunities to pass) traffic behind Jeff that caused me to try very hard to keep my speed up to very near the speed limit... I guess I shouldn't be surprised at the outcome.

And I wouldn't have been, had that been what the ScanGauge was telling me.

Oh well. Next time we'll ditch "realism" (I really did want this route to go through some city traffic as well as rural 2-lane highway traffic) and go for TRULY rural roads, practice some serious P&G, and see what happens.

The good news is that my buddy Jeff is hooked, and he never backs away from competition. All I have to do is say "bitch, I want a rematch!" and I'll have a solid competitor ready to go play.

[enkid]

Actually, I think you got pretty close to the upper limit under those conditions.

If you did an average of 35MPH, you'd probably have gotten better than 55MPG.

I average about that speed on my commute. I was surprised it was that low after I got my Scangauge.. Intuitively I would have guessed it was 45MPH.

[Loren]

Our target was an average 45 mph on this run. The 180 miles was split into three sections, and we finished 3-7 minutes late on each of them. Overall, our average speed ended up being a little over 38 mph.

I think 49-50 is about the max for the techniques that I've mastered. To get more, I really need to practice longer pulse and glide and incorporating FAS to extend the glide.

I still think there's 55 mpg out there.

[Tonavi]

Originally Posted by Loren

I don't normally cut the ignition at stop lights, but I will for this trip. That's probably worth another 1/2 mpg or so, maybe more.

I've heard higher octane can improve mpg a little. I'll be at about 1/2 tank before Sunday, so I'll have half a tank of 87. I guess it wouldn't hurt to fill up for the run using 91 or 93 octane. Will probably average to about 89 octane.

Any other ideas on how to get that last little bit of MPG without getting too crazy?

I used to stop the motor at long lights but noticed a decrease in mileage. The amount of gas the computer uses to restart the engine undoes any benefit. Also, the added wear and tear on your starter does no good. Unless the light is >10 minutes, there is no benefit to doing this.

Using 89 octane gas is what I have been doing ever since 600 miles, and I have went from getting 38 MPG to about 44 with the same driving style.

Good luck on your trip!!

[BailOut]

Hello Tonavi,

As voodoo explained all it takes to break even with the fuel usage and wear and tear of a warm start in most modern vehicles is 7 seconds of idling. This has been proven time and again, with every type of vehicle, fuel, drive line, transmission, etc. All variables have been tried and found true. Hybrid cars are designed to perform this function for you.

If you are seeing opposite results then either your MPG measurements are not accurate, your MPG measurements are not done consistently, you do no have enough data to get a clear picture (e.g temperatures, wind conditions, etc.), your personal perception is skewed for some reason or something is mechanically wrong with your vehicle.. I encourage you to begin keeping an MPG log and tracking some good data points while you experiment with the technique some more.

[Tonavi]

I will try it that way, keep a log, and keep all variables constant.

I was not making unsubstantiated claims, just sharing my experience. No disrespect to anybody.

[stripey]

Just read all this thread for the first time - compelling read and I look forward to the next hypermiling attempt.