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554 mile xB1 tank at 52.53 mpg!

184K views 2K replies 142 participants last post by  glenbrrr 
#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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#3 ·
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
 
#7 ·
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
 
#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.

 
#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.
 
#13 ·
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.

 
#14 ·
Oops. Sorry for the duplicate graph. I'll try to atone for my bad by posting the following exclusive data for my xB.
 
#15 ·
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.
 
#20 ·
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.
 
#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.
 
#21 ·
I'll paste part of another post into this thread, to keep mpg tips in one place.
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I only run my engine when my box needs to move. Starting from a cold (40º F) start, I get it rolling, and coast to the end of the block, engine off. I wait for an opening in the cross traffic, start the engine, get it up to 15-20 mph, and roll around the next corner, coasting to the end of the next block. Start the engine, turn the corner, climb a brief hill (under 10 mph) and coast the next 2 blocks. By the time my blue light goes out and I've reached 137º F, I'm 4.5 miles down the road, and my trip average is up to 40+ mpg.
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If you just start and go, with the same number (4) of stop signs, you'll be lucky to get 25 mpg for the same distance.
 
#22 ·
My best tank was 500 miles, 46mpg and intake/header/exhaust combo not affecting it at all.

The difference is, I use more than 75% foot pressure to get to 40mph, then let off so I hit 4th gear, which is better than the manual's 5th gear as far as mpg is concerned.

I limited highways to 60mph.


I might have to start hypermiling again, my past 3 tanks have been 31mpg, it's very cold out, so that's a lot of the problem.

Under average driving I get 36 mpg almost every tank.
 
#23 ·
That's excellent for an AT, Zman. I thought you sold your xB.
 
#25 ·
I usually buy my gas (87 octane Regular) at Costco. According to CARB, all California gas has been E10 since 1/1/2010.

I monitor my instantaneous fuel economy with an Ultragauge. It doubles as a scan tool to read trouble codes.
 
#26 ·
My current tank's status: 266.5 miles, and the fuel gauge isn't down to the halfway mark yet.


DTE is distance to empty - another 361 miles. I'm averaging ~53 mpg for the current tank.


Summary of today's drive - 28.9 miles averaging 65.1 mpg. It's sea level driving, not downhill like you're guessing.
 
#28 ·
I look for 250 miles at the half tank as an average tank. When I get 280, it's a sign of a good tank. I'll surely go another 13.5 miles before my gas gauge drops to the halfway mark.

My Ultragauge calibration errs on the conservative side, as I want to get at least what it shows. When I get more than what it shows, I'm pleasantly surprised. I typically get about 2 mpg better than what the UG indicates when I fill up.
 
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