[m3tr1c]

Alright never make a thread unless I got to but I'm stuck guys. My miles per tank have really gone down. I was getting 315 to a tank and over time it's gone to 260. 85% hwy 15% city driving. Once this happened I've started with the maintenance. Bought new iridium plugs, tires (old were worn), synthetic tranny fluid, synthetic oil (5w-30), and cleaned Mass-air sensor. Any ideas or things I should look into also?

Quick note on my air filter. I noticed there is like a filter on the very top but it's not removable. Is that like a post filter and there should be a removable one or does this car not use one and that's what's messing everything up? Thanks for the info.

 

[Damaged]

If any of this happened since you did any of the maintenance/changing of stuff it could be that your ecu still hasnt adjusted to the new normal.

If this has happened before any of the changes then im not sure
How many miles on your box now?are you carrying any extra weight lately?

 

[Slorocket]

Tire size remain the same?
drivin faster on hway?

I dunno. Cant think of anything that would eat 55 miles a tank. Even the addition of everything mile drain related together wouldnt do that.

Sorry

 

[5zero4]

Ummm. When you open the air filter box, there should be a filter the shape of the box. If not, you need one. The permanently attached one is for filtering gases coming back from the motor when it is off and valves are open. It's an emissions thing.


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[gmed1988]

That's about what I get normally... Only have about 8K miles on it though. Hoping it goes as the miles do.

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[alfundo]

did you unhook your battery and reset the on board comp in the process? if so it takes a bit for it to learn your mpg. are you talking the actual usage or the range when you fill it?

 

[m3tr1c]

Yea I've been using my math check the average mpg. I'm going to reset the computer and see if that helps any. Really need to figure this out. The filter will have to wait till Friday. I may as well clean the maf sensor also since it's probably filled with dust with no filter on it. Any other ideas why mpg is low is greatly appreciated. I have a 70 mile average commute so anything helps.

 

[m3tr1c]

So found out there was low tire. Only running 12 psi when taken to discount tire Co. Also got a air filter in and hopefully reset the ecu by removing battery terminals noticed miles didn't change so hope fuel maps are reset. Got a trip to houston Friday so we'll see what mileage looks like traveling.

 

[5zero4]

Good luck!


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[BrickPig]

So found out there was low tire. Only running 12 psi when taken to discount tire Co.

So what happened to your Tire Pressure Monitoring System (TPMS)? That's been equipment required by law on new US passenger vehicles since 2008. Did you remove your TPMS sensors? Or are you a First Gen xB?

Tire-pressure monitoring system - Wikipedia, the free encyclopedia

 

[m3tr1c]

A rim was replaced when I bought the xB. They never replaced the tpms sensor and the light has always stayed on. I just got a tpms sensor from eBay though. Gonna take it to discount tire and ask them to put it in the tire it's missing from and reprogram it. They mentioned they would do it no problem so we'll see what they say.
Not heading to houston after all so I'll keep you posted how mpg looks after a fill up or two.

 

[m3tr1c]

Well after all the driving i do. Mostly driving 70 mph on the highway I have done 2 fill ups and I'm only netting 23 mpg. I am still trying to see if I can improve on anything else. I cleaned the maf sensor due to finally getting a air filter earlier seeing if that helps. Also reseated the spark plugs just to see if one wasn't seated right and reset the ecu. One thing I haven't tried that I usually do with my vehicles is use seafoam and fill it through the vacuum line.

I can't seem to find it on this car though. Don't wanna risk putting it down the wrong line. Can anyone show me where it is so that I can see if this will fix my mpg issue? Also any other ideas are appreciated. Thx

 

[Slorocket]

Imo. Mostly hway drivin at 70 +, youre not gonna get a whole lot more mpg out of 'er. Thats pretty close to what I was getting with my '08 and the '11 when I did that kind of daily drive too.

Youd probably have to move into the hypermiler arena. Lowering. Drafting. Slower speeds. Higher pressure in tires.

 

[m3tr1c]

Imo. Mostly hway drivin at 70 +, youre not gonna get a whole lot more mpg out of 'er. Thats pretty close to what I was getting with my '08 and the '11 when I did that kind of daily drive too.

Youd probably have to move into the hypermiler arena. Lowering. Drafting. Slower speeds. Higher pressure in tires.

Whats surprising is that I'm basing my numbers off of how my car was when I first got it. Over time it was just gone down and I'm trying to recover what was lost. If i could get 280 a tank I'd be content.

 

[BrickPig]

Are you on the same tires as when you bought your xB, or are they new?

If new, the new tires may have higher rolling resistance than the old ones.

Have you checked your alignment lately?

I agree with Slorocket, MPGs really go down above 70. I have the instantaneous MPG readout on my 2011 constantly, the MPGs are better below 70.

 

[m3tr1c]

Are you on the same tires as when you bought your xB, or are they new?

If new, the new tires may have higher rolling resistance than the old ones.

Have you checked your alignment lately?

I agree with Slorocket, MPGs really go down above 70. I have the instantaneous MPG readout on my 2011 constantly, the MPGs are better below 70.

The tires were pretty old when i got the car bought some falkens that are factory size. The alignment is something I should probably get checked just pulls very slightly right but nothing that is major. Could even be the wind pushing the car over idk. Pretty surprised that I can't even touch 26 25 mpg on highway. I use cruise sticking on 70. Even with the instant mpg its showing over 30 gliding down the highway so idk just tossing ideas. Looking at other threads here some tend to get decent mpg for their highway drives 27+ or so. I was at one point getting 30 mpg driving From Brownsville to austin (300 Miles). Now i only get 260 even being careful with the throttle.

Anyone have experience with injector cleaning services at shops? Maybe that would help or is the remedy really just to drive slower? :/

 

[BrickPig]

The tires were pretty old when i got the car...
bought some falkens that are factory size.....I was at one point getting 30 mpg driving From Brownsville to austin (300 Miles).

Was that 30 mpg before, or after, the Falken tires?

If you didn't get an alignment when you bought the Falken tires, nor one since, then you should get one now...

 

[BrickPig]

Slower speeds. Higher pressure in tires.

Both very easy to do and free.

 

[m3tr1c]

I got the 30 mpg before the tires. Took it to a shop and the alignment was actually done on it already. I'm just wondering if the south Texas wind just sux that much and it's killing my mpg. Mornings don't seem to bad. But it the afternoons is when the wind is gusting a good 25+ mph so I'm wondering if that's got anything to do with it.
Still looking for the vacuum hose to poor seafoam down if anyone can show me where that is thx.

 

[5zero4]

There is no real benefit in putting sea foam down the vacuum. It's only good in cars with direct injection, where no fuel hits the back of the inlet valves. Just put it in your gas tank.


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