"Hypermiling" counterproductive?

[Dust]

If you take a look at my mileage, you will see that I have a few tanks in the log. The worst one was being nice to the car. No boost, slow starts, watching lights, etc. Yielded 10.4something KMPL. The next tank, before I got tires for the car, was a lot of boost, climbing a mountain, and not really being nice to it. Yielded me 15.4 KMPL. The tires were a little mismatched when I bought the car; 165/55/14 and a 155/65/14, and I filled up early on the last tank to kind of reset after buying new tires and an alignment. I used some Fuel Power Plus for the first time on the third tank, and a stronger dose on the 15.4 tank. That’s a lot of difference. Is it because I didn’t have much throttle on the 10.4 tank, and more throttle makes better mileage? What am I missing?

[mattW]

Engines actually run more efficiently (per kw/hp) at wider throttle angles so you can actually accelerate too slowly for FE and its better to cruise/hill climb in a high gear with open throttle then at high rpm/low throttle. You should probably look at your engines BSFC map to see where to keep the engine.

[Dust]

With a turbo in the mix, does pulse and glide include getting into boost too?

[Daox]

Do you have a scangauge? If so, set it to monitor closed/open loop mode. You should be accelerating as hard as you can without bumping it into open loop mode. In open loop you will be running rich air/fuel ratios and loosing the benefit of P&G.

[Dust]

No OBD2. Really wish it did though. Life would be easier. May pick up a wideband though, although the cost benefit would be rather dim.

[Daox]

Check out this dodad. It should allow you to monitor open/closed loop. I made and used one for a while on my 96 Tercel.

http://autospeed.com/cms/A_1716/article.html