Mpg help!!!
Thread Starter
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1st Gear
Joined: Nov 2010
Posts: 18
From: PHOENIX AZ
Mpg help!!!
SO im getting like 16 mpg on my a4 1.8tjus did a oil change and still feels like sumthings holding me back, changed rotors and pads, no help...its auto and it feels real heavy, heavier than when i bought him a couple months ago, any ideas anything will help fellas thanx!!!
these are my upgrades
big intercooler and aftermarket bov,
dual exhaust but only one is intact
old owner had it
these are my upgrades
big intercooler and aftermarket bov,
dual exhaust but only one is intact
old owner had it
1st Gear
Joined: Aug 2009
Posts: 235
Hi,
well in summer i get around 24mpg and in winter around 16-18mpg..
Anyways, check Tire Pressure, Change tranny fluid, bad bearing/roller? Engine could be sluggish, maybe repllace spark plug/coil packs?
the list goes on... and on..
well in summer i get around 24mpg and in winter around 16-18mpg..
Anyways, check Tire Pressure, Change tranny fluid, bad bearing/roller? Engine could be sluggish, maybe repllace spark plug/coil packs?
the list goes on... and on..
2nd Gear
Joined: May 2008
Posts: 1,030
From: SLC, Utah
^^ +1
Definitely check tires; low pressure and the size of the wheels can affect it. For example, bigger/wider tires produce more friction on the road, diminishing fuel economy. Next, make sure you've got a clean air filter. You'd be surprised how much a clogged air filter can affect performance and fuel economy, especially if you drive in boost a lot; air flow is critical. It'd also be a wise investment to change the fuel filter, especially if you just recently bought the car. There's no telling when it was changed last via the previous owner and just like air, fuel supply is critical to mileage and performance. Spark plugs are also a must; as with the fuel filter, if you haven't already changed them after buying the car, there's no telling when they were done last and for as cheap as they are, just replace them anyway and scrutinize the gap; if you've got a tuned ECU (which the previous owner could have done and not told you about) you'll need to run a smaller gap. After you've checked/replaced those things, if its still lagging and getting bad mileage, then I'd start looking into the more technical things like transmission and the mechanical parts of the engine.
Definitely check tires; low pressure and the size of the wheels can affect it. For example, bigger/wider tires produce more friction on the road, diminishing fuel economy. Next, make sure you've got a clean air filter. You'd be surprised how much a clogged air filter can affect performance and fuel economy, especially if you drive in boost a lot; air flow is critical. It'd also be a wise investment to change the fuel filter, especially if you just recently bought the car. There's no telling when it was changed last via the previous owner and just like air, fuel supply is critical to mileage and performance. Spark plugs are also a must; as with the fuel filter, if you haven't already changed them after buying the car, there's no telling when they were done last and for as cheap as they are, just replace them anyway and scrutinize the gap; if you've got a tuned ECU (which the previous owner could have done and not told you about) you'll need to run a smaller gap. After you've checked/replaced those things, if its still lagging and getting bad mileage, then I'd start looking into the more technical things like transmission and the mechanical parts of the engine.
Administrator
Joined: Jul 2006
Posts: 11,670
From: Binghamton, NY
^^^per what A4Cragman says, gap on new plugs for stock boost should be .032" and for a chipped computer it should be gapped down to .028".
Bad mpg is affected a lot by old O2 sensors (which degrade over time and cause losses in economy long before they're bad enough to throw a code). The MAF is also suspect. And just to throw this out there, common wisdom out there is that due to the closed induction setup on this car, with the MAF metering and OEM recirc valve, use of an atmospheric blowoff valve can create rich spikes that over time will foul your O2 sensors and clot the catalytic converter. It's very possible you are seeing the effects of that.
Bad mpg is affected a lot by old O2 sensors (which degrade over time and cause losses in economy long before they're bad enough to throw a code). The MAF is also suspect. And just to throw this out there, common wisdom out there is that due to the closed induction setup on this car, with the MAF metering and OEM recirc valve, use of an atmospheric blowoff valve can create rich spikes that over time will foul your O2 sensors and clot the catalytic converter. It's very possible you are seeing the effects of that.
Thread Starter
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1st Gear
Joined: Nov 2010
Posts: 18
From: PHOENIX AZ
hmmm thats a long list of things to look over...im gonna have a busy weekend...i was thinking about conecting the other side of the exhaust and install a test pipe with 3 inch piping, maybe itll help the exhaust flow but i dont wanna "back spool" i think its called ...correct me if im wrong...
thanx for da info guys
thanx for da info guys
