From what I gather from this thread and from the EPA links provided, the testing for MPG is done on a dynamometer (treadmill) and not on an actual road. So, the wind resistance would not be a factor in the estimates posted on the sticker.

I always assumed that the reason the xB mpg estimates were less than the xA was due to the shape of the vehicle. Now it seems that this isn't a factor (for the epa estimates).

Just curious - does anyone have an opinion on why the estimated mpg for the xB (30/34 for automatic trans.) is quite a bit less than the estimated mpg for the xA (32/38 for automatic trans.) ?

The xB isn't that much heavier (about 85 pounds ?) than the xA, so you wouldn't think that would be the reason.

Eric

 

The Xa is more aerodynamic

 

Ok, so all this time I've been dissapointed with my gas milage on my Xb, thinking the sticker was way off, cursing Toyota for lying to me. The other day I actually did an accurate check (did the math all by myself) and it turns out that my box is getting 33 mpg! Much better than I thought and that was all highway, all with the AC blasting. I think the fuel gauge is kinda misleading because the reserve tank (whats left after the needle hits E and the light comes on) is actually pretty big. Its at least 2 gallons, maybe closer to 3. Considering we have 12 gallon tanks, thats substantial, and can be kinda misleading.

 

Right, I know the xA is more aerodynamic. But for the EPA test, aerodynamics wouldn't have an effect on a car driven on a treadmill would it ? I mean, it's not a wind tunnel. It's a car on a treadmill in a room basically. So the car is basically sitting still (relative to the room) with the wheels turning the treadmill.

So, with that in mind why are the EPA mpg ratings for the xB lower then the xA ?

>> The Xa is more aerodynamic

 

u guys can sit here and go bla bla bla epa this bla bla bla toyota that...when it comes down to it....my 2k civic si got the gas mileage stated on the sticker sometimes better.....my 03 accord v6 gets dead on what the sticker said....02 vw jetta gets better then the sticker rated.....my scion gets worse then the sticker rated....nuff said

 

Not true. The coefficient of drag is a factor in how the dynamometer is programmed. The xB has a higher Cd, so it has to work harder on the dyno at a given speed.

Dynamometers can simulate all aspects of road conditions, including hills, wind, aerodynamics, etc. The beauty of using the dynamometer is that it is completely controllable, whereas mother nature isn't.

George

 

Just in, some highway mileage data:

5-speed xB. Air conditioning on for nearly entire trip, 198.9 highway miles, (measured by GPS), 5.174 gallons, filled to brim at both ends of trip.

198.9/5.174=38.44MPG. (wow!)

This trip was purely highway, from Atascadero to Paso Robles on the US101, to Blackwell's Corner on CA46, to Maricopa on CA33, via CA166 to I-5, then south over the Grapevine to Santa Clarita. Speeds ranged from 55 to 75MPH, climbing the grapevine at 65 in 4th. Car was loaded with two adults and two children, as well as 60 pounds of luggage.

This mileage figure seems rather high to me, but the driving was probably close to optimum for mileage.

For the entire round trip, we went 458 miles and used 12.98 gallons of gas. This gives a mileage of 458/12.98=35.28MPG Still not too shabby!

This mileage , while mostly highway driving, includes about 40 miles of city/suburban driving.

The odometer is a bit off as well. On stock tires, 198.9miles measured by the GPS is equal to 190.3miles measured by the trip odometer, so the trip odometer seems to read about 4.3% low. This would affect mileage calculations if you use the trip odometer for this purpose. For example, if you got a true mileage of 30MPG the number would be 28.7 if you use your odometer to measure the miles driven.

George

 

George,

Thank you very much for this info. So, I guess the drag coefficients are something probably determined in a wind tunnel (by Toyota or by the EPA) and as you say they can simply program the drag coefficient into the dynamometer to account for wind resistance. Cool.

Just for the record, I have an xA (not an xB) but have been getting acceptable gas mileage results as well. Averaging about 35 mpg driving to work (about 40/60 city/ highway). Haven't had a chance to test the mileage on a long - all highway trip though.

Eric

 

The other thing to note on the epa mileage for highway is the average operating speed, below 50mph. The faster you go, the more resistence as everyone knows, and I doubt many people drive 60 even on roads with a 65 limit to save on gas. I'd bet the average person goes 70-75 at least, so you're losing a good 15-20%mpg according to the epa datasheet posted above.

I bet if if your grandma drove the xB, she'd average 35-40mpg. :D

 

If my grandma drove the xB, I'd get her on the talk show circuit ASAP! Resurrection hits the ratings big!

One revelation of driving with a GPS is that your average speed is a lot less than you think that it is. For the trip I mentioned, my average speed is 51MPH despite my feeling that I maintained a speed between 55 and 75 all the time. It only takes a short time at a slow pace to _really_ lower the average!

George

 

I am waiting for the verdict on my little Xb as well. I just got it last weekend and it is down to half a tank already and I have only gone about 100 miles. I am hoping that either the dealer didn't fill it up all the way or that the fuel guage is off a tad and that there is a lot more gas still left in her...

SHU

 

I've filled up twice now, and each time, the gas pump stops at 9.4 gallons. I top it off, and squeezed out a total of 10.5 gallons of gas. I think the neck inside the fuel door is too long, and it backs up quickly. This kinda sucks, because topping the fuel off every time is bound to lead to some spillage.


BTW, after the second tank ran out, the car had gone 320 miles, and I was kinda dissapointed....guess it's still better than some of you are getting.




Skylab™

 

i have heard from scion coorp that we should wait till 2000 miles to _____, and that the epa test area done no ac windows up...i dunno ALL my other cars have always gotten REALLY close to the rated mpg..even WITH the a/c blasting....the dealer actually told me that if i dont get better mpg on this trip i am taking then i need to bring it back in , cause its not right ...just my .02

 

Mileage on the xB. . . .

First tank - 27.94 mpg. Mostly hwy. To/from dealer, then on trip to Eastern Shore of MD.
Not bad considering my Dodge truck got 10-13 in town - 15-17 hwy. (And that was babying it.) NOW you know why I bought the xB. (Plus its stylish good looks.)
Doubled mpg by trading. Worth it. :D
(I think the dealer stopped the pump when it cut off automatically & didn't top off. Too bad. I fill it to the cap.) 12 gals isn't a lot.

Second tank - 29.34 mpg. Hwy driving.

Third tank - 34.4 mpg. combined city / hwy. This tank calculated by driving back and forth to work from So. MD to Wash., DC for a week. Speeds from 5 mph - 65 mph.
A/C not used. Unusually cool week. Rainy.

Fourth tank - 30.40 mpg. Same traffic conditions as third tank, only used A/C a LOT.
Back to HOT & Humid weather. Welcome to DC!!!

All in all, considering what I WAS getting outta my truck, I am NOT complaining.
My wife has a G. Caravan and she spent $42.00 this week on 1 tank of gas. $2.04 9/10 per gallon. (She wants MY box now!!!) Ha!

29 - 34 mpg beats the hell out of 10-13!!!

For me, pretty darn close to the stated mileage of 30 - 34.

 

I just bought a TCM Scion Xb last week. We are relatively happy with it however........... we only got 203 miles to the first tank and I am halfway through my second and it only has 105 miles more. For a total of 309 miles to a tank and a half. That is less than 17 MPG. Is this normal???????

Also....I have been reading the posts regarding buying new cars off the lot. Ours had 12 miles on the odometer and was suppossedly brand new. Is this too high or am I being paranoid?

Thanks for the help. I am a naive young female who just bought my first car and want to maintain it as well as possible....... :oops:

 

No it isn't, unless you're a wild driver! If it continues, see the dealer for a diagnosis. Keep careful written records of fuel usage.

12 is quite reasonable. That amounts to one or two test drives. If you expect to test drive a car, you should expect to buy a car that someone else has test driven!

Asking a question is the first step on the road to wisdom. Don't sell yourself short!

 

My xB has a total of 700 miles (have had it less than a week!) first tank I got 32 MPG, the second totaled 34.5 MPG- and Im not complaining. My Ford Focus got if im lucky 30 MPG, and usually got 27 MPG . BTW- the focus had 110 HP and was 2750 pounds.

 

My first tank - 290 miles on 9.5 gallon - Roughly 30mpg. City and highway driving with AC on 90% of the time. Babied it most of the time (Breaking it in)

 

Hey brarsandeep, I just realized we took delivery on our xB's on the same date! I filled up again today ( I now have almost 800 miles ) and went 165 miles on 5.1 gallons=32.5 . 50/50 hwy/city. A/C on 70% of the time.

 

800 miles in one week....WOW!!! That's a lot of driving. Hope you are enjoying every mile!