[Kag]

Hello all.
I'm a newbie scion owner, bought a 2011 xb auto. I really like the car except the fuel economy isn't that great. It's got 18,000 km on it now and I'm wondering if there are any upgrades that will improve the fuel burn.
Also wondering if a small turbo would give it some extra punch at not a pocket breaking expense.

Thanks

 

[phobic]

turbo would be very expensive, regardless of the size. there's a lot of parts and labor to adding a turbo.

not sure of any upgrades that will make the fuel consumption better. you can always try a cai and a more open exhaust, generally that helps a bit.

and welcome to the site!

 

[Kag]

I was a VW TDI driver before (had 5) but I got sick of the repairs. This little toaster is a great family ride as I have a baby and its not a mini van. Yeah I know most on here bought it to customize while I bought it because it's practical. Funny enough I see more older folks driving them then the young target market.
My only complaints are it's jumpy off the start and at night there is lack of dash lighting in front of driver. That and I thought it would have gotten better economy.

 

[PDXBOX]

I was disappointed in the economy as well, but found if you strip the airbox of the snorkel and extra tubing, remove the carbon filter from the top of the box as well as the fins on the inside of the box it has helped me get an ave of 22+ in town better than the 17-18 I was getting before. Also if you have the dash nobs turned to the Defrost it will kick in your AC unit giving worse mileage as well. So 2 free mods. Dont use Def. and shave down that airbox! Here is a thread I made on another site:Shaved/smoothed airbox mod will give you aroundt 6-8MPG better in town!

 

[TrevorS]

Fuel economy is all about how you drive. Don't count on spending money on any bolt on to help you out. It comes down to your foot and driving choices. I have made a pile of mods to mine (one at a time), the only things that've helped my fuel economy are maintaining tire pressures, favorable weather and traffic conditions, and me thinking fuel economy whenever I drive.

I was disappointed in the economy as well, but found if you strip the airbox of the snorkel and extra tubing, remove the carbon filter from the top of the box as well as the fins on the inside of the box it has helped me get an ave of 22+ in town better than the 17-18 I was getting before. Also if you have the dash nobs turned to the Defrost it will kick in your AC unit giving worse mileage as well. So 2 free mods. Dont use Def. and shave down that airbox! Here is a thread I made on another site:Shaved/smoothed airbox mod will give you aroundt 6-8MPG better in town!

Funny, nothing at all I did with my intake did a thing for my fuel economy. Course, I wouldn't expect it to. The only fuel that get's injected is that metered according to the MAF air flow detector and the standard closed loop AFR. Take off the snorkel and you'll be able to suck more air and the engine will be able to work harder and when it does, the mpg will drop -- it's as simple as that !

 

[2K11XB2E351]

removing unnecessary items from your car would keep the weight down. Even the spare donut weighs like 20 pounds.

 

[TrevorS]

removing unnecessary items from your car would keep the weight down. Even the spare donut weighs like 20 pounds.

True, but it takes material weight reduction to result in material MPG improvement -- and the spare is pretty useful if you get a flat !

 

[2K11XB2E351]

True, but it takes material weight reduction to result in material MPG improvement -- and the spare is pretty useful if you get a flat !

Haha yeah absolutely, sometimes I just wanna rip my front seats out of the car cos I dont know if this applies to other XB owners but my factory leather seats without the arm rest does not recline back up when I pull on the lever. I have to pull the lever with my left hand while I'm having to twist my right arm back to pull it back up. (same thing for the passenger seat with reversed hand order) If someone is sitting behind me, I would ask them to give a little shove on the back of my seat.

Anyhow, getting back to the topic, that extra 20 pound donut is probably good insurance :biggrin:

 

[alfundo]

the 4 mods i made and noticed minimal mpg improvements have been CAI, lowering, lesser weight wheels, and spoiler...and im not really sure about the spoiler. the gain i noticed may have come from the change to summer gas.

the biggest fluctuations come from your foot. i drive 30k a year and get 29 - 31 mpg summer and 27 - 29 winter. im not that anal about it and dont break out the calculator at every fill up. my numbers are based on the factory gauge which i know to be about 1 mpg better than actual. i reset my AVG MPG at each fill and one of my trip meters as well. less braking = better MPG, leave a bubble around you and coast.

 

[PDXBOX]

Fuel economy is all about how you drive. Don't count on spending money on any bolt on to help you out. It comes down to your foot and driving choices. I have made a pile of mods to mine (one at a time), the only things that've helped my fuel economy are maintaining tire pressures, favorable weather and traffic conditions, and me thinking fuel economy whenever I drive.


Funny, nothing at all I did with my intake did a thing for my fuel economy. Course, I wouldn't expect it to. The only fuel that get's injected is that metered according to the MAF air flow detector and the standard closed loop AFR. Take off the snorkel and you'll be able to suck more air and the engine will be able to work harder and when it does, the mpg will drop -- it's as simple as that !

Decreasing parasitic drag on the intakes flow is how it helps with mileage. It is an air pump, also cooler more dense air (via CAI vent) will give more hp and torque at a lower rpm (1%hp per 10degree drop at the intake) needing less fuel for each horse given a driving constant. Most people like to hear the roar after they mod and never see a bonus. Keeping driving habits steady is key. You can even get better gas mileage when you don't use the cruse control.:cheers:

 

[PDXBOX]

Also a real CAI uses aftermarket MAF sizing, (larger) than stock but still within adjustment for the ECU. This will be putting more air and more fuel in. By just doing an airbox shave/ mod you are keeping the MAF size stock, just allowing free-er flow and cooler temps.

 

[rodnic]

Hearing about some of the other members mileage results has made me feel even better about "Boxanne"! She has been doing pretty well, although, as expected, winter weather has dropped the figures considerably. I have to agree with TrevorS about maintaining tire pressure; it is very important. I am going to try some of the mentioned airbox improvements (already has a K&N) and see what happens. If the news I heard yesterday about 150.00 a barrel for oil within a year materializes, every little bit will help.

 

[alfundo]

Boxanne! fugging lov it!

 

[TrevorS]

Decreasing parasitic drag on the intakes flow is how it helps with mileage. It is an air pump, also cooler more dense air (via CAI vent) will give more hp and torque at a lower rpm (1%hp per 10degree drop at the intake) needing less fuel for each horse given a driving constant. Most people like to hear the roar after they mod and never see a bonus. Keeping driving habits steady is key. You can even get better gas mileage when you don't use the cruse control.:cheers:

Drag on air flow through the filter box has no different conceptual affect than changing the inlet pipe diameter -- it results in some variation in max air flow. However, as I already pointed out, fuel metering depends on the AIR mass seen by the MAF not by flow restriction. Air temperature, pressure, and flow are measured by the MAF in determining the ingested air mass. Changing the air flow restriction changes the ability of the engine to work (ie. ability to perform), but it doesn't change its AFR. The only way internal air box mods can improve MPG is if the AFR changes -- the ECU says no!

 

[TrevorS]

Also a real CAI uses aftermarket MAF sizing, (larger) than stock but still within adjustment for the ECU. This will be putting more air and more fuel in. By just doing an airbox shave/ mod you are keeping the MAF size stock, just allowing free-er flow and cooler temps.

OEM and recognized CAI and SRI manufacturers use 3" diameter pipe at the MAF. If the engine detects AFR issues via the 1st O2 sensor, it'll utilize that data to correct the AFR. If the discrepancy is significant, it'll generate a CELL.

Also a real CAI uses aftermarket MAF sizing, (larger) than stock but still within adjustment for the ECU. This will be putting more air and more fuel in. By just doing an airbox shave/ mod you are keeping the MAF size stock, just allowing free-er flow and cooler temps.

What after market MAF's are you referring to that deliberatly provide inaccurate information to the ECU? Still, even if they did, the O2 sensor still provides a block against rogue MAF sellers -- though I don't see what that (or CAI/SRI) have to do with you increasing max air flow through the air box. Modest increase in air flow of warm air doesn't lower its temperature, it just means there's more air meaning more fuel is needed to maintain AFR.

 

[TrevorS]

By the way, I probably should mention I hand calculate my MPG fill-up to fill-up, and I agree that I get better numbers in the summer than in the colder months when the winter blend gas kicks in ! At the moment, the only thing still stock in my intake is the OE airbox and MAF, having installed a high-flow filter in it and 3" pipe in front of and behind it. I've also ported the pipe interiors and TB for minimum turbulence, plus my intake feeds from the left fascia vent. Guess what? Not one shred of evidence of MPG improvement -- great for performance though !

 

[PDXBOX]

Here is an example of the MAF section that I am talking about: $65 dollar Ebay intake review and while it is not seen on the out side here is more info from AEM: TECH TALK:
Most modern fuel injected cars use a Mass Air flow (MAF) sensor to determine the air flow rate into the engine and meter fuel according to input from the sensor. The relation between the voltage output of the sensor and mass air flow is adversely affected by a shift to a larger diameter intake tube because the airspeed is reduced. This causes the MAF sensor to “under report” air flow causing a lean condition or triggering a Check Engine Light. To accommodate MAF sensor reporting, many intake systems reduce the diameter of the intake tube near the MAF sensor to stock or near stock size because of the need to maintain the correct air speed for the sensor to report the correct flow rate to the ECU.

AEM's ETI Intake Systems use an alternative design approach that allows the intake tube to maintain its diameter, resulting in more air flow into the throttle body. The ETI Intake System allows AEM to tune an engine for even more power by avoiding any tube down-sizing that will reduce overall airflow and horsepower. Instead, the ETI electronically communicates with the MAF sensor to ensure an accurate amount of fuel is being delivered even though the tube is larger in size than the stock system. This means the vehicle maintains the calibration as intended by the factory while enjoying the benefits of our custom designed aftermarket intake system.

When I calipered the maf section of the box I thought it was "slightly" smaller than the 3" pipe I had next to it...(I will go out and check again) You can also buy a MAF calibration tube from Spectre that has different size sleeves to adjust the amount of air measured. My mazda could only adjust for a 10% fuel trim difference... and this is where I used this type of calibrator with monitored fuel differences and fuel trim adjustments.

 

[TrevorS]

As long as you're not changing the MAF calibration, the AFR will remain the same and so will the MPG, if you change the calibration, the ECU will use the wide-band to correct it. Therefore, we are dependent on the OE ECU (which is remarkably flexible, thank goodness) and it behaves in the fashion I described above. Unless you WOT into open loop, you are constrained to CL 14.7 AFR, and MPG basically comes down to your driving habits, conditions, gas quality, and how you maintain your car.

If you want to tune it, then you're looking at a piggyback and the only one available for our cars is Unichip. Although our ECU will support a considerable range of mods, it's very single minded about the AFR.

Obviously, modifications to the vehicle exterior can also potentially modify MPG at high enough speeds, though they can also hurt it and are not necessarily worth their cost. For example, the Scion rear spoiler does essentially nothing in terms of MPG, so that's not a reason to buy one, but it does a great job of keeping the rear window clear (the usual design intent of a factory spoiler) and I love mine !