Hi yall,

owneds4 here, I have a little problem i'd like to check out myself here. Well basically, My S4 is runnin nice and I like it a lot, my only complaint is bad gas mileage, I do mostly city driving and occassionally hit the highways to go down to the dealer, or Home depot and etc.

It all started last month. I was pretty low on gas, and I filled up at the nearest place, which was Exxon (i know, it sux) and i filled up a full tank 13.3 gallons or so.

Long story short, I got about 145 miles on that full tank before my Gas light came on. That was with some moderate, to occassional aggressive driving style, but definately not pushing it all the time, just on open roads i'd be rolling at about 40mph, then drop it into 2nd gear and take off a couple times and shut down at 100mph, not all the time.

So i thought to myself, wTF? how come only 150 miles for a full 91 octane tank. Ok ok whatever, blamed it on bad gas (exxon) and aggressive driving. So I go get gas at my place of choice 76, and its not the cheapest 76 station either, I fill up and it costs me 33 bucks or something another 13.4 gallons, 91 octane.

This time i'm running completely conservative. I baby the pedals, at intersections when the light turns green, i barely step on it, and come to a slow start just till i can gain enough momentum, to barely rest my foot on the tip to keep cruising. No racing, no laying down the hammer at all.

So yes, there is a slight gas mileage improvement, when i started the miles left sensor gave me 330 miles which i was excited about. But it seems like each time I start my car and drive, that interval drops like crazy, now i'm at 140 miles in, w/ maybe 1/4 a tank left and the meter reads 70 miles left which will get me about 210 miles total.

Keep in mind, i did do some freeway driving, maybe 60/140 miles, i completely babied the pedals while driving this time, slow accels, light cruising, and Such horrible gas mileage on good gas too.

So i complained to dealer, and of course they told me "If no codes pop up, there is nothing wrong with your maf or Coolant sensor"
So i'm like wtf? why such low mileage.

keep in mind here, i have never made it over 200 miles on a full tank yet. I always fill up at like 1/4 left.

So my question is:

Should i disconnect my MAF to see if it runs better? What is the consequence of disconnecting your MAF? what does the MAF do? And can someone link me to a Tech article on how to disconnect maf?

 

...or you've never made it over 200 miles till the car literaly stalls out from no fuel?

Fuel Sending unit going bad is not uncommon. In my car, the behavior was early gas warning light came on, low range, and the indicator in the cluster would never go to Full.

 

personally, I've always filled up when the gas tank still has some juice in it. So i've never seen my Trip counter go over 200. Probably not relevant. I was just tryin to emphasize that i've never really tested out how many miles I can go on a full tank

 

but when I had the fuel sending unit go out, it was all jacked up.

I would say I needed gas, even though my trip counter was barely at 175m, so I'd fill up and only put in about 8 to 10 gallons, then the fuel gauge would say 3/4 tank or so.

All was right again with the new fuel sending unit.

 

and you're driving quite aggressively. Reset your average mpg meter at every fill up and report back after your next fill up and tell us what reading you're getting. With mild city use (mostly highways), I get a little over 20 mpg each tank. I consistently run down to zero miles to empty and then fill up. Sounds like you're filling up as soon as the light goes on. I usually get just over 300 miles to a tank, and I can get over 400 if I hit the open road and set the cruise at 65/70.

 

how many gallons of fuel are you typically putting in the tank?

 

1. Coolant temp sensor: Its $5 for the part and 15 minutes to swap it out so just replace it.

2. MAF: Log Block 211 and check out the fuel trims in Block 032. Post the results here. Usually from the data you can determine if your MAF is on the way out.

3. EGT Sensors: Not sure how to acurately determine if there is a problem with them short of them generating a DTC. You can examine the EGT sensor output in one of the VAG datablocks (can't remember which) but if its an intermittent issue, I'm not sure which you'll see. They're pretty expensive to replace as well.

That said, 145 miles on a full tank is way too low. You should definitely see 200+.

-Dave Pramanik

 

when people post their mileage being like 240 or 250 like RyanS4 below. Are they talking about 250 until the gas light comes on? or 250 until they have stalled on the side of the road due to no gas.

 

RKA, about 14 gallons.

 

I've been driving this thing like a baby, local driving, but less stop and go, and slow accelerations and some highway stretches. is this normal?