I got 224 miles on 7 gallons ($25 @ the pump); wich is about 3/4 of the tank. I Calculate that and I barely got 30 tp the gallon.

 

I don't get it. I've always got above 30mpg. A/C on, 75-80mph, hills, etc. My last fill-up was 8.7 gallons and 306 miles. Figures out to just over 35mpg. This is nothing new for me. I can't believe mileage varies so much between cars!

 

just too many variables affect mileage... tires, wheels, cargo, driving style, performance mods, maintenance, tire pressure, commute distance, hills, weather, passengers, traffic, city driving, blah blah blah... hell, i've read that DIRT affects gas mileage... and most of these affect mileage negatively... it makes it almost useless to directly compare mileages without comparing all of those other variables... and it's not like any of us are going to go trade commutes and/or cars just to test this...

personally, with my stock automatic and "ideal" commute conditions... 60 mile round trip to work... no cargo... two people (the wife and i)... 65-80 mph ("try" to keep rpms around 3K)... virtually no traffic... 90-95% freeway... and one uphill stretch and i averaged 32 mpg consistently... when i went to lightweight 15's (w/oem tires) two years ago... my average went up to 33.5... more recently the wife found a new job... now that i commute alone, i have seen my mpg go up a bit more, the last two tanks have been around 35 mpg...

 

“… Our first acceleration times for the GXP were somewhat slower than Pontiac’s claims, and company officials suspected our car may have been delivered – and then tested – with regular fuel. After we retested with premium, the GXP redeemed itself, blasting to 60 mph in 5.6 seconds and through the quarter- mile in 14.2… big improvements of 1.1 and 1.2 seconds, respectively…”
--Car & Driver, October 2006, page 119, “Road Test Soltice GXP”

 

well gxp is a different car. you can't really use that as an argument. i'm not saying the person who claims premium gave them worse mileage is right or wrong, but i am saying you are comparing apples to oranges. find an article that talks about it with an xb.

 

I'm a new xB owner. I got a full tank when I purchased it, drove 320 miles and put in 11 gallons to full.

 

Just an update -

I did a typical mixed city/highway run that did not consist of an incredible amount of uphill/under 40 mph driving. This trip had several across town drives averaging 40 mph and a couple highway trips averaging 60 mph. I filled up after only 1/4 tank and got 34 mpg.

Lesson here - definitely consider where you live relative to where you're going (Lots of uphill? Under 40 mph?) when looking at MPG calculations. It's too early to tell if my xB is just even more underpowered than a typical one, but this definitely speaks volumes of the underpowered nature of the xB.

 

The excerpt from the Roat & Track test was not about more mileage on premium, it was about more power. And it applied to all cars having high compression engines with a knock sensor, the xB and the GXP included.

Such engines are electronically managed to run on regular gas, but make more power on high octane gas because their knock sensor does not need to retard the ignition under full throttle to prevent knocking.

As the article says, both Pontiac and Road & Track agreed that regular gas was the cause of the GXP's poor first run, and knew to improve the performance with high octane gas. Similarly, the 2005 xB was rated at 108 hp because it was tested on high octane.

 

Duplicate.

 

Did you ever take it into the dealer, and what did they have to say regarding your mileage issues?

 

The change in the xB's HP ratings was due to a tightening of the SAE standards.

See this thread and others for discussion: https://www.scionlife.com/forums/vie...422214#1422214

RichC

 

I'm waiting until first oil change - documenting every fillup. I don't have but another 700 miles to go. In all honesty, I don't think they'll have a single thing to say about the mileage. If I lived in a different part of town, my MPG would be vastly different.

 

An experiment:

I do ~60% highway driving, 15" wheels, 35psi, manual tranny, moderate driving technique, some AC.

I know no one is going to want to hear this, let alone actually do it, by here it goes: This tankful, I did not take my box above 60MPH. Mostly stayed ~55MPH. MPG increased from 32-34 up to 38MPG.

 

Exactly, the new SAE standards said the rating of an engine had to be based on whatever fuel was recommended in the car's Owners Manual.
That was in the thread at:
https://www.scionlife.com/forums/pos...uote&p=1066693
And Scion did not want to change the recommended fuel in the manual to premium, for what was supposed to be an economy car.

 

I calculated 32mpg on my last tank. Manual 06.

 

I noticed the same thing with my manual transmission xB. To attend Exposed 06, I drove from Louisville to northern Ohio and back.
Going up on a 2-lane road at 55-60 = 37 mpg.
Returning by Interstate at 60 mph = 42 mpg.
It just takes patience to continually use light throttle, shift at 2000 rpm, and not exceed 3000 rpm. As someone commented, "get a life".

 

I've done the same thing a few times with my auto and have gotten 37-38 but it ain't no fun

 

Well, that depends on you notion of fun, and maybe the road you're driving on. Going down route 97 in central Washington and Oregon, there are plenty of reasons (IMO) to treat the speed limit as a maximum instead of a minimum.

 

I meant it more like sticking to only 55 mph is NEVER fun unless you are on a very tight twisty road.

 

I got 38 keeping at 65 or below and not using my AC. Of course that was in the Spring time............