[09noo_x_b]

sautan did you ever go back to the dealership or anything about this?

[Exposure101]

Originally Posted by eggie

What wheels do you have? How much do they weigh?

Fill up. Reset trip odometer. Drive until like half tank. Fill up and note gallons used to fill up tank again.
Divide miles drive by gallons used and that will give you the miles per gallon.

I know this was stated above, but from reading teh post it did not register if you understood that or not.

Heck for kicks, you can swap wheels and tires and see what happens.

Also, an engine should be driven easy for the first 1000 miles to properly break in the internal components. Then do an oil change and swap in synthetic, Mobil 1 is cheap and works just fine.

I def agree with all of this....especially the swapping to synthetic oil!!! Maybe add some lucas oil additive to it....not a lot like 5-10%

[sautan904]

I think I will go back to the dealer. I have not swap the wheels because the other xB is currently being worked on. The stereo dude took 3 weeks to get my car done and still have problem and now fixing it. Dealer took 10 days to get all the TRD parts!!! I just got the car back and will swap the wheels probably tomorrow. Another tank of testing with stock wheel. If still persist, it will go to dealer. The problem, they always comes out with "No Problem Found" and if you pressure harder, they might not happy! i dunno, i will try.

[sautan904]

OK, finally I switch the wheel with my other xB. The result is amazing. I cannot believe the difference MPG can change with the wheel and rubber.

xB Blackberry Auto

Old MPG - 17MPG Combined. with 19" 5-Axis Wheels
New MPG - 27MPG Combined. With 16" Enkei Wheel and Stock Rubbers

xB Gold Rush Manual

Old MPG - 30MPG Combined. With 16" Stock Wheel and Rubbers with Fujita Intake.
New MPG - 23 MPG Highway Mile for 40 Miles (no traffic) on 5-Axis Wheels.

5-Axis Wheel 19" 235-35R 19

Well, I do not suggest to size up wheel and tires if you are looking for MPG. Good thing for my Gold xB, it's the show car with all TRD mods and Custom interior. So i do not drive as much. Will add Supercharger in December!!!

Eventhough i only drive for few days but i am so sure. I reset the meter and drive for 2 days... 50/50 local and fwy and read 27.x earlier. Never I saw it reached over 19MPG in the past!!!

[TartanJack]

For wheels and MPG affect . . . "lighter is better."
Less rolling weight means less mass to get moving and to stop with the brakes. Also, less "effort" to change direction for a lighter rim.
On top of that, lighter means that the suspension has to work less to "suppress" the bouncing of a lighter unsprung mass.
(I could continue, but I won't.)
One of the main reasons I want Rota Slipsteams in 16x7 is that they weigh less than 14 pounds (6-8 pounds less than the 20-22 pounds of the stock steelies), not counting tires (which should add approx. 20 pounds). Oh, and tires of a smaller ratio tend to be heavier, as the sidewalls are stiffer and have more internal structure.

In short, "Lighter is Better."

[jahfakin]

Originally Posted by cnstarz

you cant trust the computer anyways,.....

why can't you trust the computer?

I'm the opposite...I always trust the computer....mainly because heat throws off gas pumps (gasoline expands during the hot summers/temp). So in the summer time, you are getting ripped by the gas stations. This naturally affects the MPG calculation, when manually done.

the computer, on the other hand, gets its data directly from the injectors. a more reliable source.


p.s. I think some states have heat sensing pumps, that automatically adjust to the temperature and dispenses the exact amount of fuel everytime.

[WhiteNoise]

Originally Posted by jahfakin

why can't you trust the computer?

I'm the opposite...I always trust the computer....mainly because heat throws off gas pumps (gasoline expands during the hot summers/temp). So in the summer time, you are getting ripped by the gas stations. This naturally affects the MPG calculation, when manually done.

the computer, on the other hand, gets its data directly from the injectors. a more reliable source.


p.s. I think some states have heat sensing pumps, that automatically adjust to the temperature and dispenses the exact amount of fuel every time.

Hawaii is one such state but it sets the pump temp at 80 degrees. That said the tanks are stored well below ground where it takes longer for them heat up. Also a 15 degree increase in temp only changes the volume by 1%. Note this only happens after 60+ degrees.

[jahfakin]

Originally Posted by WhiteNoise

Hawaii is one such state but it sets the pump temp at 80 degrees. That said the tanks are stored well below ground where it takes longer for them heat up. Also a 15 degree increase in temp only changes the volume by 1%. Note this only happens after 60+ degrees.

yeah, if the pump is calibrated for 60 degrees, and it's 90 degrees outside in the middle of summer, you are getting ripped. It may not seem a lot, but it adds up. based on your calculation, a 25-gallon fill-up of 75 degree F gasoline equates to a loss of nearly one quart. The same fill-up at 90 degrees F equates to nearly a half gallon.

[CrazyMPG]

Originally Posted by sautan904

OK, finally I switch the wheel with my other xB. The result is amazing. I cannot believe the difference MPG can change with the wheel and rubber.

xB Blackberry Auto

Old MPG - 17MPG Combined. with 19" 5-Axis Wheels
New MPG - 27MPG Combined. With 16" Enkei Wheel and Stock Rubbers

xB Gold Rush Manual

Old MPG - 30MPG Combined. With 16" Stock Wheel and Rubbers with Fujita Intake.
New MPG - 23 MPG Highway Mile for 40 Miles (no traffic) on 5-Axis Wheels.

5-Axis Wheel 19" 235-35R 19

Well, I do not suggest to size up wheel and tires if you are looking for MPG. Good thing for my Gold xB, it's the show car with all TRD mods and Custom interior. So i do not drive as much. Will add Supercharger in December!!!

Eventhough i only drive for few days but i am so sure. I reset the meter and drive for 2 days... 50/50 local and fwy and read 27.x earlier. Never I saw it reached over 19MPG in the past!!!

wow those 19" rims make a difference...btw...do you know the weight for those 5 axis 19" rims with tires versus the stock steelies with tires?

[TartanJack]

Originally Posted by jahfakin

{snip}, a 25-gallon fill-up of 75 degree F gasoline equates to a loss of nearly one quart. The same fill-up at 90 degrees F equates to nearly a half gallon.

Please let me know how you fit 25 gallons in an xB, either generation . . .

I generally put in 6-9 gallons per fill-up.
Of course, over 3-4 fill-ups, that would make some difference.

[BlackKnight]

Originally Posted by TartanJack

Please let me know how you fit 25 gallons in an xB, either generation . . .

I generally put in 6-9 gallons per fill-up.
Of course, over 3-4 fill-ups, that would make some difference.

Not to mention that the pumping station tanks are required to be below ground, and there is a level below ground (4-5 feet I believe) where it is no longer affected by the change in surface temperatures and stays at around 54 degrees (if I recall correctly). so the gas you pump should be the same/ or as close to the same everyday no matter what the temp. However once it's in your tank if you over fill and park in the sun you may see spillage.

[TrevorS]

Originally Posted by sautan904

OK, finally I switch the wheel with my other xB. The result is amazing. I cannot believe the difference MPG can change with the wheel and rubber.

xB Blackberry Auto

Old MPG - 17MPG Combined. with 19" 5-Axis Wheels
New MPG - 27MPG Combined. With 16" Enkei Wheel and Stock Rubbers

xB Gold Rush Manual

Old MPG - 30MPG Combined. With 16" Stock Wheel and Rubbers with Fujita Intake.
New MPG - 23 MPG Highway Mile for 40 Miles (no traffic) on 5-Axis Wheels.

5-Axis Wheel 19" 235-35R 19

Well, I do not suggest to size up wheel and tires if you are looking for MPG. Good thing for my Gold xB, it's the show car with all TRD mods and Custom interior. So i do not drive as much. Will add Supercharger in December!!!

Eventhough i only drive for few days but i am so sure. I reset the meter and drive for 2 days... 50/50 local and fwy and read 27.x earlier. Never I saw it reached over 19MPG in the past!!!

In addition to lighter is better, narrower is also better when it comes to mpg. Wider tires have greater rolling resistance and also scrub more when changing direction. The other factor is inflation, lower inflation pressure results in higher rolling resistance. Conversely, over inflation will result in more rapid tire wear!

[dreeder72]

Just for comparison: Im driving an 09 XB with 2700 miles. I average 27mpg city and 33mpg highway, these figures were determined with daily city driving and 1 trip out of state for highway. Everything is stock. I did notice that when the fuel meter read empty I would only get 11-12 gallons into the 14 gallon tank. So I opened the gauge cluster, pulled the gas meter needle off, tossed a gallon of gas in the trunk area and drove it until it ran empty. I then placed the needle back onto the gas gauge pointing to the correct "empty" position. now when I fill up the needle goes well past the full mark but when it reads empty it is really empty. Another thing I noticed was the fuel range feature is NOT accurate, I have had it read 0 miles left till empty and continued to drive for another 50 miles.

[TartanJack]

Originally Posted by dreeder72

Just for comparison: Im driving an 09 XB with 2700 miles. I average 27mpg city and 33mpg highway, these figures were determined with daily city driving and 1 trip out of state for highway. Everything is stock. I did notice that when the fuel meter read empty I would only get 11-12 gallons into the 14 gallon tank. So I opened the gauge cluster, pulled the gas meter needle off, tossed a gallon of gas in the trunk area and drove it until it ran empty. I then placed the needle back onto the gas gauge pointing to the correct "empty" position. now when I fill up the needle goes well past the full mark but when it reads empty it is really empty. Another thing I noticed was the fuel range feature is NOT accurate, I have had it read 0 miles left till empty and continued to drive for another 50 miles.

It's called a "reserve" . . .
Most cars have the gauges designed with a reserve, so that people don't run completely out of gas. Modern fuel injection systems don't "like" running completely out of gas.
I like to keep an idea of how much reserve my vehicles have.
The xB2 has more than 2-3 gallons. So, I should be able to drive about an hour before I am completely out, so don't panic but look for a decent station.
The most I have put in is 11 gallons, the light was on but wasn't on for that long.

My Miata (the "other" car) has 1.5 gallons reserve and an 11 gallon tank, so the most I have put in it is 10 gallons, when "on fumes" and on "e" for a while.

[dreeder72]

I'm aware of what a reserve is and it's purpose. I guess that it's just personal opinion that 2-3 gallons of reserve is excessive on a 14 gallon tank, the reserve is 15-20% of the capacity. I just prefer to know when I'm empty as opposed to guessing how much is left. That's why I moved the needle.

[TartanJack]

-----Okay.

[darita]

Originally Posted by sautan904

OK, finally I switch the wheel with my other xB. The result is amazing. I cannot believe the difference MPG can change with the wheel and rubber.

xB Blackberry Auto

Old MPG - 17MPG Combined. with 19" 5-Axis Wheels
New MPG - 27MPG Combined. With 16" Enkei Wheel and Stock Rubbers

xB Gold Rush Manual

Old MPG - 30MPG Combined. With 16" Stock Wheel and Rubbers with Fujita Intake.
New MPG - 23 MPG Highway Mile for 40 Miles (no traffic) on 5-Axis Wheels.

5-Axis Wheel 19" 235-35R 19

Well, I do not suggest to size up wheel and tires if you are looking for MPG. Good thing for my Gold xB, it's the show car with all TRD mods and Custom interior. So i do not drive as much. Will add Supercharger in December!!!

Eventhough i only drive for few days but i am so sure. I reset the meter and drive for 2 days... 50/50 local and fwy and read 27.x earlier. Never I saw it reached over 19MPG in the past!!!

So, is the consesus here that with an auto trans and 19s, mileage can go down dramatically or was that just is one specific case? What about others with 19s...what mileage do you get?

[seppuku27]

Originally Posted by darita

So, is the consesus here that with an auto trans and 19s, mileage can go down dramatically or was that just is one specific case? What about others with 19s...what mileage do you get?

Its all about wheel weight and auto trannys natural get worse gas mileage than standard trannys. Bigger wheels weigh more unless your willing to pay thats why you get worse gas mileage.

[darita]

Originally Posted by seppuku27

Its all about wheel weight and auto trannys natural get worse gas mileage than standard trannys. Bigger wheels weigh more unless your willing to pay thats why you get worse gas mileage.

So, with a standard trans and middle weight 19s, what do you think I could expect for mpg?

[seppuku27]

Just make sure the 19 with tire is the same weight as the stock rim and tire you will see the same mpg.