Archngl

I have a 2005 xB with low miles, and I do all highway driving, but I keep coming out around 28 mpg.
I'm supposed to get 30 in town, and 34 on the highway, and I feel I'm really short.
Does anyone else have this problem? Is there something I can do to get better fuel efficiency?

I've installed a K&N air-filter to see if that helps, but any info would be appreciated!

-Ken

ack154

iTrader: (7)

Have you changed wheels/tires at all? Have you checked tire pressures? How about alignment?

Any engine mods at all?

OMAC

Check your tire pressure and watch out how fast you are traveling. I get just over 30 MPG if I don't go over 70MPH. Anything over that starts to noticibly reduce my mileage.

Archngl

I'm usually around 75... I'll have to try going slower. As for wheels/tires, I have the 15" 7-spoke rims with stock tires.
No engine mods to speak of, and my tire pressure is at 29 to 30 depinding...

tanakasan

How much air pressure in the tires?

I have an 06, stock, w/auto. Doing 95% fwy, I was getting between 30/33. Averaged around 30.5/31.5. All city I get around 27/29.

I run 35psi on the stockers. Going from 32 to 35 psi added .5 mpg. You should be getting more than 28 if you drive real EZ. xB mpg goes down fast if you stomp on it.

BTW, on long uphills, I drop into third (OD off) and get better mpg winding out at 4K+ rather than stepping into it at 3K and lugging. The little motor likes to rev and is more efficient up there.

ack154

iTrader: (7)

The speed could have a LITTLE to do with it, but I'm not sure 6mpg worth.

I used to cruise at 75 or more all the time on the highway. But I've noticed a definite difference when driving around 65... 2-3mpg depending on the amount of highway per tankful. So I drive slower now on the highway.

Archngl

Isn't it dangerous to over-inflate your tires?

ack154

iTrader: (7)

If you grossly overinflate them, yes. And you can cause irregular tire wear (the middle will wear faster if they're overinflated). But a couple lbs will generally not hurt.

soylentgreen

Overinflation decreases rolling resistance...but it also decreases the vehicle's controllability becuase less tire surface touches the road. Inflate your tires to the pressure indicated inside the driver's door.

Anyway, Ford recently published a study showing that 38% of fuel usage is related to driver habits and vehicle maintainance. Bottom line is on the highway try to maintain a constant speed. Too much speeding up and slowing down kills fuel economy.

Easyoboe2

I have a 05 xB, manual. Just returned from a trip, 475 miles each way. 1,148 total miles, 37.631 gallons of gas = 30.50 MPG. Three adults in the car with clothing, etc for 5 days. Most of the mileage was highway, 65-70 MPH, faster when necessary, with cruise control. There is, and has always been, a lot of BS about gas mileage. These are the facts, and I am an accountant.

JDMJim

I got 33mpg's in my xB. That was mixed city and highway. I just putzed around.

Easyoboe2

OOPs, I forgot. 205-50 on 16".

MikeC

iTrader: (1)

How are you guys getting such exact numbers? I figur if you are dividing the Miles you travel by the Gallons of gas in the tank then that method is flawed unless you are absolutely runnung the car out of gas. Am I wrong?

To help out on the mileage increse, if you take out the owners manual, and open to the specs to check what the spark plugs are gapped to, and then check your plugs you will notice that the numbers do not match, and the plug's gap should be slightly increased.Mine were at .027" and I believe the reccmended is .032". I increased the gap, and in turn my mileage. Hope this helps.

Easyoboe2

Figuring MPG has nothing to do with running out of gas. You record the mileage and than you fill up with gas, Then you do this again, and again , and again. There are too many variables in the gas pump meters, the ambient temperatures and the way you drive to figure your gas mileage on one fill-up of gas. Then, you devide the number of gallons into the miles driven, and you have your MPG, which will always be variable.
I told you I am an accountant, and a long-time back yard mechanic. Now shut up and believe me.

chadfo

Fill the car, up drive, and fill up again. The amount you put in the second time is what you used. It's not exact unless you fill it up to the cap because the automatic cutoff will be different at each pump but it's close enough.

I have a 70 mile trip to work each day. 40 is back roads where I normally do about 65 and 30 is interestate where I do about 70. I gained a few MPG by not using my cruise control. I guess the backroads were just hilly enough to negate the benfits of the steadiness of cruise.

oldboxman

Always remember to check and fill your tires when they are cold!!!!!When you drive on them they heat up and the pressure builds.

Just something to remember

Max

A better way of calculating mileage is to calculate over several tanks. More data=more precise. Calculate total miles driven by total gallons consumed. I use Excel.

Using this, and taking notes in the spreadsheet as far as temperature and highway/city driving and speeds, you will learn a lot.

Averaging 80-85, I get about 30 mpg. Keeping it 65-70, I get 33-35, and all city driving, I get 29. Once I went 60-65 nonstop without A/C and got 37.

15"wheels, auto, exhaust, CAI. Averaging 31ish.

Archngl

I have a 2005 xb... what's my tire pressure supposed to be at? 29? 30? Should I go to 32 or 35 cold?

BUCKO

I heard that switching to SYNTH oil for the engine and tranny can increase your mileage, by how much i dont know... but I'm planning on it once i get to 5K.

XbbbbBox

I have an 05 XB Auto. I do a lot of mileage for work and record every tank for my mileage expenses.
Once you go over 70 mph I have found the mileage drops quickly. The best mileage I get is when I keep the RPM's below 3000.
If I average 75 more or less I get 28-29. At no higher than 70 and conservative I get 31-32. The best I have ever got is 34.5 mpg. I usually run my tires at around max pressure labeled on stock 15"tires(not what is on door). In my opinion not much difference in handling with increased pressure in stock tires, if any thing it handles better, and stiffer ride. When I put my 4 snow tires on in the winter I lose 1 mpg.
I have K&N stock filter replacement. Also at 31,500 miles I changed plugs and they were worn much more than I expected. I just put in a set of platinums and appears my mileage went up slightly but I need to run a few more tankfuls to be sure. Also I always have 150 lbs worth of gear in my car.
FYI - my GPS always says my speedo is off by 2-3 mph - Speedo says 70 and I am going 67-68. Try a tankful going always less than 3000 rpms and your mileage will go up.
Also in hilly areas (like Vermont in the northeast) the engine labors heavily to maintain 65mph -70mph plus over the hills and often shifts to lower gear (especially with cruise on) and this hurts mileage.
Hope this info is helpful!