I am just wondering why lately Ive been getting 15-16 mpg.
Tires are at 32. Premium 91 / 93 octane (depends on which station). Driving habits are the same. New tranny fluid at 55k per MID....Does something need to be aligned in the motor? I also had the throttle body cleaned up at 56-57k

Any thoughts? 2009 TL with 66k.

Appreciated :-)

 

Make sure your air-filter is not filthy... takes 2 seconds, and sometimes it is the culprit.

 

all clean :-) I was wondering what the valve alignment might do. Probably nothing. My best guess is lousy winter fuel additives...if they exist....or just flat out bad batch of fuel. Acura recommends a tune up at 105k, correct? Would 70k be premature since Ireally don't know the history of the car prior to my purchase at 30k?

 

a dirty air filter wont affect gas mileage.

also, your valves are probably NOT that out of spec and would happen over time.

if you suddenly just noticed poor fuel economy, its not the valves.

you could try pumping up your tires 3 or 4 psi to UP MPG.

I also think its winter fuel blend.

 

I know that you have mentioned this before when I have advised people to check their air filter. Also, I know that the MAF/computer will compensate, but when an air filter is filthy it will sap gas mileage... I have seen it, and the return to normal fuel economy when the filter is changed, on a few cars that have modern ECUs/emission systems.

 

It's always great to have both sides of the argument; so that the OP can make an informed decision.

 

Mine has actually changed over the past month as well, but it has improved from about 19 to 22 mpg. I assume it's because I haven't been using my AC and also because the dealer inflated all of my tires to 40 psi when I had it in for warranty work. It's been a nice change!

I know this post doesn't help you at all OP, but good luck getting your issue resolved.

 

+1 on this I was averaging 19 mpg (pure local driving) over the summer and am now pulling 16's. It's the winter fuel.

 

It's normal to see a drop in MPG in the winter months for a whole bunch of different reasons such as:
1. Air is denser in the cold and creates more wind resistance
2. Friction increases from oil and drivetrain fluids thickening
3. Cars will idle high longer to get to operating temperature
4. Tire pressure decreases and causing more rolling resistance
5. Allowing your car to warmup kills MPG since you're averaging 0 mpg while the car sits and burns fuel

Winter fuel mix is also another reason as noted above.

 

Is this why I seem to walk slower too?

Seriously, though, I'd never considered this as a factor...but on the flip side, wouldn't denser air improve combustion?

 

^it does!

my car loves the colder air!

 

Yes it does, it's at highway speeds the denser air affects MPG in a negative way.