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Pishtaco
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3,956 Posts
Discussion Starter #1
I know when most of you think performance, you're thinking about going fast. But let's face it, our 108 hp, FWD, aerodynamic barn doors are about the poorest racers ever made.

99 wheel horsepower coupled to FWD means anyone with 90 hp and RWD will beat you. Anyone with 100 hp and FWD will beat you. Anyone with AWD will beat you. Darn near anybody driving anything will beat you. The only races you'll win are when the other guy is laughing so hard, you get a hole shot on him.

Bolt on a thousand bucks of headers, intake, and exhaust, and 99% of today's bone stock cars will still beat you, including every family sedan, taxicab, minivan, and SUV out there.

So let's talk about where a 1.5 liter engine shines - fuel economy. When our engines are warmed up, we burn .11-.14 gallons per hour idling - less than half of what a typical family car will drink. We can cruise all day at 35 mph and average nearly 55 mpg at that speed.

I've made a game of hypermiling my xB since I bought it over 17,000 miles and a year and a half ago. In that time, I've averaged 46.7 mpg under all driving conditions, including a 7200 mile cross-country round-trip to Miami in the Summer, with AC running and four people inside.

My last tank was my record distance tank, 554 miles on 10.547 gallons, for a 52.53 mpg average. How do I do it? Not with performance mods. My only mod there is this WAI, which didn't improve my fuel economy one iota.

I drive slow, and I drive smart. Stoplight drag racers typically get single digit fuel economy from light to light, and lower that even more idling. The average driver has his foot on the gas pedal half a block from the next red light. I've been gliding to it for three or four blocks. I let the jackrabbits trip the sensors, and try to glide through the lights without touching gas or brake pedals.

Our boxes are aerodynamic barn doors. Push them over 55 mph, and fuel economy plummets. At 70 mph, I get 32 mpg. At 55, I get about 45 mpg. At 31 mph, I get 55 mpg. So I go slow on highways, and prefer to take slower frontage roads.
80% of my mpg gains come from going slow. Questions?
 

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SUSPNJNKY
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5,599 Posts
yea - i noticed when I go 45mph i get around 35/36mpg but realistically going 31mph is not a good idea. my friend gets 42mpg out of his d16y7 civic and he is rocketing everywhere. So even though we can achieve great fuel economy we have to sacrifice time in driving slow places and when you are traveling long distances it's not good.

I can solidly obtain 32/36 mpg for every tank which is better than most cars any ways. civic's will always beat us for fuel economy
 

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-EC HFD YO-
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6,809 Posts
damn hondas hahaha
i get on average 35 mpg also but 52 mpg is nuts! lol
 

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Registered Box Offender
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281 Posts
even though i get about 35mpg, im satisfied with what i got. but i agree, 52 mpg is crazyness. i give you props on that. lol
 

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Registered
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19,896 Posts
i bow to u on this one. i thought i was the ish gettin 47mpg on one of my socal trips back early 09 but 52 is nuts. and on that trip i pulled everything i thought i could also. outa gear for over 9 miles straight comin down the grapevine, following semi's when i could switching leading every 30 min or so with the other car i was caravaning with
 

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Pishtaco
Joined
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3,956 Posts
Discussion Starter #8
My other car (an SE-R Spec V) was my go-fast car. I'm glad I didn't go for a WRX, because the curve just ramps up from there - the Neon SRT-4, the Mazdaspeed 3, the STI, the Mitsubishi EVOs...

So, since our xBs are pretty much the bottom feeders in the pool (it sucks knowing xAs, Yaris', Echos, and Fits can all beat us), I decided to go the other way.

 

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Pishtaco
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3,956 Posts
Discussion Starter #10
? The ECU keeps our engines running at stoichiometric (14.7:1 A/F) ratio. We can't make them run leaner (without a huge amount of effort) if we try. Effect is a noun. Affect is a verb.
 

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3 Posts
My wife gets horrible gas mileage on the pkwy, a lot of inclines going 70-75mph, drains the gas.

So by looking at the chart, if she were to slow down to 60 she would gain another 5-10mpg?
 

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Pishtaco
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3,956 Posts
Discussion Starter #13
My wife gets horrible gas mileage on the pkwy, a lot of inclines going 70-75mph, drains the gas.

So by looking at the chart, if she were to slow down to 60 she would gain another 5-10mpg?
Absolutely. Look at this graph, for my family's three cars. The leftmost peaks are pulse and glide test results. The dip following is next-to-top gear cruise control. The remaining part of each graph is top gear cruise control. The
'06 Hyundai Elantra is a slushbox. The '02 Nissan Sentra SE-R and '06 xB are MTs.

I learned about slowing down on 800 mile round-trips to my mom's. My SE-R only averaged 26 mpg at 72 mph with cruise control. I slowed to 62 mph and got 33-34 mpg. Slowing down to 55 mph, I got 38 mpg, and no longer needed a gas fill-up midway on the trips down or back.

 

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Pishtaco
Joined
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3,956 Posts
Discussion Starter #14
Oops. Sorry for the duplicate graph. I'll try to atone for my bad by posting the following exclusive data for my xB.
 

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Your Box-Fu is strong...
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43 Posts
Hmm, after considering all of your evidence and mulling over your well planned and beautifully executed graphs and charts, I have to say: Whatever. I can afford gas. I LIKE drag racing between lights. It's all about enjoying the drive. If you enjoy it by monitoring your MPG, congrats, you're winning as a Scion driver. If I enjoy driving by mashing the pedal and seeing how far I can push the envelope with the local fuzz, I too am winning.

Still though, that kind of fuel conservation is amazing dude, I just don't have the patience nor concern for it.
 

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Ain't too Funk to Druck.
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17,243 Posts
very interesting indeed. unfortunately, I have this disease for non-conserving-fuel-could-care-less-about-mpg-lead-footitis. i have to get to "B" quick. i definitely give you props for the research. you're a gentleman and a scholar. :)
 

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Pishtaco
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3,956 Posts
Discussion Starter #19
Patience comes with $50 gas fills, and/or enough speeding tickets. If I wanted to race around, I'd take the money many of you spend on intakes and exhausts, and buy a used sports bike. A used $1000 250 cc bike will beat any xB with bolt-ons. A used 1000 cc bike will beat any street legal car.

But sure, different strokes for different folks. It's just that xBs are the bottom of the barrel to start races with. I give you folks props for trying, but a used GSX-1100R is a whole lot cheaper and faster.
 

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Pishtaco
Joined
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3,956 Posts
Discussion Starter #20
Nice! Great write up too. Since you have a manual, do you coast a lot of the time, like down hills going into neutral.
It depends on the hill. I coast down gentle hills. On steep ones, our xBs have deceleration fuel cut-off, which cuts off the fuel injectors, and uses even less fuel than idling. DFCO cuts in at 1NZ-FE engine speeds >1500 rpm when you're in gear and running closed loop. That's essentially at any speed >35 mph in 5th gear once the engine is warmed up.
 
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