In most of my driving the rate of acceleration doesn't matter, therefore wouldn't it be most efficient to shift at about 5k with WOT? (Yes that's driving like a nut, but that's just for acceleration.)theholycow wrote: Power output per unit of fuel at or near WOT is better than at part throttle. Do that at peak torque RPM and you're making a ton of energy out of a ton of fuel. If you actually need to make that much energy out of fuel then it would be most efficient to make it that way, but if you don't then it is a huge waste.
For normal driving on the road, the most efficient choice is to open the throttle as much as possible without going open loop*, and keep RPM as low as possible while producing the desired level of acceleration.
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please critique what I'm doing
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Re: please critique what I'm doing
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Re: please critique what I'm doing
I agree with accelerating harder and getting up to speed quicker then cruising in a high gear after that is a fuel efficient way of driving. I would argue that its more fuel efficient than short shifting with light throttle and slowly getting up to speed using all the gears.DrJerryrigger wrote:2800 is not needed, most situations I could keep it under 1500, heck I could probably keep in under 900 if no one is behind me.
I might be making this up, but I thought I read somewhere that fuel usage to power output (at or need WOT) is best at the RPMs that give the best tourqe (often about 4000rpm for gasoline engines).
As to my shifting system; I feel using all the gears leaves me not giving any power for too much time. If I'm using nearly WOT I need to fully close it for nearly a second before disengaging the clutch so the engine doesn't rev up, which would take more time to compensate for.
I also agree with potownrob that when you're new, you want to shift sequentially and go through all the gears. This will help you get your timing down and know the rpm differences between gears etc.
As for your question, you can probably get away with shifting from 2 to 5 etc on flat ground but when you live in a hilly area you will need all the gears. You will also want to shift sequentially when you are accelerating hard up to higher speeds.
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Re: please critique what I'm doing
I think you're doing fine overall because you are driving safely (not uber-hypermiling), not impeding others too much, and crushing your EPA fuel numbers. I would say that you could consider experimenting with changing the RPM where you shift to see how much it affects your economy. Perhaps do a couple of week pseudo-experiment where the only thing you change is the RPM where you shift. Go low one week (say 1800 or so) and then go high another (say 4000 or so) and let us know the results. I, unfortunately, don't get to drive a manual EVERY day, just most days. Something about being safer to put my kid in a far newer car.. blah blah blah .
Of course you would notice something like that, matt.mtheis wrote:Sorry to nitpick, but the w59 is a truck transmission. Did you mean c59?DrJerryrigger wrote:The car '04 matrix, 1zz-fe and a w59 (1.8l straight four and a 5speed).
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'11 Ford Fiesta Hatchback SE 5MT
'14 Giant Escape City 24MT
'97 Honda Civic EX 4AT - Retired @ 184,001 mi
For Pony!
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Re: please critique what I'm doing
80% throttle. WOT would cause your ECU to ignore the O2 sensor and go to enriched pre-programmed fuel tables.DrJerryrigger wrote:In most of my driving the rate of acceleration doesn't matter, therefore wouldn't it be most efficient to shift at about 5k with WOT? (Yes that's driving like a nut, but that's just for acceleration.)
I don't know if it would work. Honestly I haven't considered it. As Squint suggested, experimentation is in order. A-B-A-B-A-B-A testing, ad nauseum, until you're confident enough in the results.
Personally I wouldn't, though. That kind of daily driving is hard on the car, and an easy way to get cops to look for your car and watch for you to make one little mistake so they can nab you and rape your insurance rates.
Looking at a BSFC map for your engine, it looks like your best bet is 2800-3200 RPM when you can properly use all of the energy made.
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watkins wrote:Humans have rear-biased AWD. Cows have 4WD
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Is there an easy place to find that for other cars? I'd be curious to find out what Clifford's looks like.
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I do an image search for engine or car model BSFC map. For example, 1ZZ-FE BSFC map. That one was nicer than the usual one that I find if I find one at all. What engine is in Clifford?
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watkins wrote:Humans have rear-biased AWD. Cows have 4WD
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Not sure what his engine's name is but he has the 2.0 TI-VVTtheholycow wrote:I do an image search for engine or car model BSFC map. For example, 1ZZ-FE BSFC map. That one was nicer than the usual one that I find if I find one at all. What engine is in Clifford?
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Thanks cow! The difference in efficiency isn't that big, I'm sure sloppy foot work at higher rpms could easily kill the difference. I need to get a obdii Bluetooth plug so I can do some a b a b a b testing on half mile runs rather than full tanks.
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Ecomodder's wiki page has a bunch, maybe some similar if not the exact engine. But remember a turbo adds an additional variable to an already hard to equate to real life chart.tankinbeans wrote:Is there an easy place to find that for other cars? I'd be curious to find out what Clifford's looks like.
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There's no shortcut good enough to say your data is dependable. Even the best collected data in short runs will never be more useful than a year of A-B-A tank tests. OBDII data in specific is particularly imperfect; it is collected in larger intervals than optimal, and usually can't directly access fuel rate.
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watkins wrote:Humans have rear-biased AWD. Cows have 4WD
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Re: please critique what I'm doing
Hypermiling a Ram 1500 EcoDiesel to 38.1 mpg
A very non-optimized fuel smileage endeavor on a truck with junk in the trunk and not even broken in yet.
http://green.autoblog.com/2014/05/09/hy ... el-38-mpg/
A very non-optimized fuel smileage endeavor on a truck with junk in the trunk and not even broken in yet.
http://green.autoblog.com/2014/05/09/hy ... el-38-mpg/
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Huh?Rope-Pusher wrote:Hypermiling a Ram 1500 EcoDiesel to 38.1 mpg
A very non-optimized fuel smileage endeavor on a truck with junk in the trunk and not even broken in yet.
http://green.autoblog.com/2014/05/09/hy ... el-38-mpg/
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Re: please critique what I'm doing
I'm going to have a hard time doing a b a b a b testing as I almost always end up going on a non commuting trip in ever tank. I guess I could start filling Monday and Friday...
Well I'm going down to the cape this weekend so I'll need a fresh tank when I get back.
Well I'm going down to the cape this weekend so I'll need a fresh tank when I get back.
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Re: please critique what I'm doing
You'll get used to Rope-Pusher. He's quite a character -- and an incredibly valuable, irreplaceable resource. He can be eccentric, posting tangents and off-topic posts and using extreme homonymism to write nearly nonsensical posts for us to decode into sense. He's also an industry insider in exactly the segment that concerns us here. I'm not going to go as far as saying I would have failed converting my Buick to manual without his help, but it's possible, and he sure provided TONS of incredibly useful, accurate information.
A-B-A-B-A-B-A testing can indeed be difficult like that. That's why you have to do it so much; you can't just compare a series of 5 tanks and have undeniable data, but long-term averages with consistent A-B switching absorb single-tank outliers. Filling Monday and Friday can help to more quickly get an idea of what your results will be, but personally I hate filling more often than necessary.
A-B-A-B-A-B-A testing can indeed be difficult like that. That's why you have to do it so much; you can't just compare a series of 5 tanks and have undeniable data, but long-term averages with consistent A-B switching absorb single-tank outliers. Filling Monday and Friday can help to more quickly get an idea of what your results will be, but personally I hate filling more often than necessary.
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watkins wrote:Humans have rear-biased AWD. Cows have 4WD
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Re: please critique what I'm doing
buried somewhere in the article was something about stuffing the fuel tank because they could do that repeatably and reduce the error of their fuel usage determination. Also, driving for a long distance helps reduce fuel mileage calculation errors as well - measurement errors have less effect when divided into a greater number of miles.
It interests me to consider what fuel smileage figure they may have achieved had they been carrying a load of sailboat fuel under a tight tonneau cover and had mebbe another 10,000 miles on the truck before they started the trip.
It interests me to consider what fuel smileage figure they may have achieved had they been carrying a load of sailboat fuel under a tight tonneau cover and had mebbe another 10,000 miles on the truck before they started the trip.
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