Latest MPG...Something seriously wrong

[x_rayted711]

Well, just filled up today. And like I've been stating for months, my MPG sucks! 206.7 miles and 9.8 gal. Figure it out! 21 MPG! I cleaned my AEM air filter yesterday to see if that would help, but it has only 13,000 miles on it and it really wasn't very dirty! Please don't tell me it's my driving or that I figured it out wrong. I FILL the tank completely every time and EVEN IF I didn't get it TOTALLY full on the last fill-up, it shouldn't affect it to the extreme that it did....so it's not that. I don't 'hotrod' the car, race people, no jackrabbit starts, and almost always do the posted speed. So what gives? PLEASE HELP! Edit: I failed to mention that I have 17" wheels/tires and kept at 32-34 psi, but have always had them, so this wouldn't be why there is a sudden drop in MPG

[x_rayted711]

BUMP! For some help! Should I clean my MAF sensor? Plugs? Convert to peanut oil? NEED HELP!!!

[elusivedragon]

sometimes i wonder how mpg is really measured honestly

reason being im at half a tank and ive driven 154 miles....that puts me at approx 308 miles for a full tank....thats more than i seemed to get in my old corolla and my brother only goes 240-250 miles on a tank in his Neon or his old Focus

so....300+ miles per full tank im more than happy with ...weird thing is i think the xB fuel tank is 11.9 gallons

so 308 divided by 11.9 = 25.8 mpg

seems weird to me!!!

[elusivedragon]

oh have you tried gas treatment? have you tried various gas stations just to make sure your not getting crap somewhere?

[x_rayted711]

I guess I should have stated in the first post. I use Shell 87 Octane and almost always the same station(and pump, for that matter). I am in CA. so I know the gas is slightly lower standard(ethanol).
BTW, the way you figured out the milage would only work if you run it completely out...i.e. the 11.9 gal. The way I figure out my MPG is to divide the amount purchased (gallons...9.8 in this case) into the amount driven(206 this tank)...came up with 21 MPG.
I have been complaining about my milage since we got our xB, but this last fill-up REALLY ticked me off.
No, I haven't tried gas treatment, but may get some injector cleaner next tank...and at this rate, it's going to be pretty quick.
Thanks for the response though. I'm at my wits end!

[Tomas]

(I normally run Chevron, but the one time I filled up with Shell I dropped 4.6 MPG on my xB. Apparently *my* xB did not care for Shell from that station.)

[LilBlkBox]

I used Citgo gas this past time and got almost 2 mpg more. But, that was probably due to my driving and not the gas. I average 27-29 because of my 18" wheels. I am not complaining at all though.

[x_rayted711]

Well, I WAS complaining about MPG when it was a consistant 28-30...Now I guess I should have been ecstatic! Not being a butt here but would you be complaining if it dropped over the course of 1 tank from 27-28 to 21 MPG? Like I said, not trying to upset anyone, but WOW, what a difference!!!
I will take it to the dealer tomorrow morning.
Tomas, I will start using a different gas next tank. I always have had good results in previous cars with shell(they have 94 octane in most states), but for some reason, as you said, my box MAY not like it either. Should I clean the MAF and how do I do it?
Thanks Tomas and LiLBlkBox for the responses!

[elusivedragon]

the MAF can get dirty if your doing like an intake install or something ive heard ...not sure how to go about cleaning it

i know which part it is thats all lol

im going to have to re-calculate my mileage and do it right lol

[x_rayted711]

I mentioned the MAF because I heard it can get dirty if you over oil the filter...I cleaned the filter yesterday for the first time, but I don't know whether the filter comes pre-oiled when new or if the dealer maybe over-oiled it....or maybe they got the MAF dirty when they installed the intake...I don't know. Like I said, I don't think my milage has EVER been up to par, but the sudden drop has me extremely worried as to a bigger problem. I hope there is an easy fix.

[grizzly_choppers]

Okay, first, manual or automatic? Second, city or highway driving? Note that highway only counts if there's constant speed and no traffic jams (I only mention it since you said you are in CA).

Now, almost nobody gets the EPA rating since they're done under such wierd conditions. If you drive on a closed course at a constant 48mph at sea level then yes, you will see the EPA estimate, otherwise, no, you won't. However, it is a very good RELATIVE comparison between cars since they are all tested the same way.

I have been getting 20-25 mpg in my manual around town lately (with about 60 highway miles per tank) and I drive like a maniac. 22,200 miles on the clock.

So, DON'T TOUCH your MAF. You have a 95% chance of screwing it up, a 4.9% chance of it doing nothing at all, and a .1% chance of it doing anything for your mpg. If you're really sour on what mileage you're getting, try some different gas from a different station first (try 2-3 tanks) and then take it in to the dealership.

I'm just trying to be helpful, please don't take this as any kind of personal attack. It's not.

Good luck!

-Alex

[x_rayted711]

Thanks grizzly...but you aren't seeing whats got me bugged! I went form 30 to 21 in ONE TANK!
I have an auto and this last tank, as well as most, have been city.
I dropped roughly 10 MPG in one tank...see why I'm worried now?
Thanks for the reply though!

[Ericvpellegrino]

Originally Posted by x_rayted711

Thanks grizzly...but you aren't seeing whats got me bugged! I went form 30 to 21 in ONE TANK!
I have an auto and this last tank, as well as most, have been city.
I dropped roughly 10 MPG in one tank...see why I'm worried now?
Thanks for the reply though!

Where did you fill up when you noticed that difference drop in one tank. Possibly water in the tank from a ____ty gas station? Get water remover for the gas and use that three tanks in a row.

[grizzly_choppers]

Ah, I missed that.

Well, yeah, get it checked out at the dealership.

It may, however, still be the fault of the fuel. I don't know how it is in CA, but many states switch out to "winter fuel" in October and November. I have experienced this both in Colorado and here in Iowa. Generally, I notice a fairly large dip in fuel economy for a tank or two when the switch is made and then it rebounds to the normal MPG. This happened to me again this year last month.

If they use winter fuel in CA, it could be part or all of your problem.

-Alex

[hip_2b_sqr]

I've had my Xb about 1.5 years now and have 24,000 mile on it. I have the AEM cold air intake and dc sport headers, borla twice pipes (duals). In town I usually get 26-29 mpg and highway trips 28-30. Sometime worse due to heavy stop and go traffic and lots of time I won't get over 45 mph during the work week drive. I am not disapointed with the milage because I know more hp's does not equal more mpg's. It is an even trade in my book. I would much rather have that little bit more get up and go and let my gas milage suffer a bit. But still, 26-30 is not bad milage these days.

Wonder how a supercharger will affect the milage?

[TheScionicMan]

True, they do use a winter blend here and this is around the time they switch IIRC. Couldn't hurt to have the dealer check things out, if you've got the time and they installed the intake...

How many total miles on the Box? A set of plugs probably wouldn't hurt, even if it isn't the problem.

[x_rayted711]

13,000+ miles... I didn't think it would need plugs for another 15,000-17,000 miles...i.e. 30,000 mile service. I will drop $10-20 for plugs if it'll help!

[Simplyscion]

I bet it was just crappy gas...no need to freak out about it...wait for another 2 tanks and if the problem is still there, then go get it checked out...you could have a clogged fuel filter for all we know...maybe try some injector cleaner. I had the turbo on my xB and got about 19 mpg city(in boost a lot) and about 23 highway...the gearing in our cars doesnt really help either...tend to wanna stay up in the higher RPM's to get some decent speed.

[x_rayted711]

Thanks guys. I didn't take it in today but was going there tomorrow. I will try injector cleaner next tank. I hope this helps...And also will try a different brand/station next tank! Thanks to all for the help!

[elusivedragon]

just calculated my mpg - currently @ 29 mpg

and im very happy with that! going about 310 miles per full tank or more, blows away what my 2000 corolla did, or my bro's old focus and his current 05 neon

my 29mpg is considering im a little heavy footed off the line sometimes, also on the highway i cruise at around 75

im a very happy box owner