Sudden drop in gas mileage

[Cumby]

My 05 V8 4x4 has consistently got 17-18 MPG . I have just over 90000 miles and in the last week or 2 have noticed my mileage averaging around 14-15 MPG. That's all based on the onboard computer. Haven't checked it manually yet. I haven't done anything to it before this change, except increase my tire pressure from 32-35 psi. My mechanic checked the plugs not long ago and said they looked ok, nevertheless, I haven't had it "tuned up". Just wondering what might cause such a sudden drop like this...if there's something in the maintenance schedule that could be the cause.

 

[RL Lemke]

When the air filter and mass airflow sensor are both checked and found to be clean, blame the gasoline formulation. Thank-you Congress for the renewable fuel mandate (I.E.: ethanol), and EPA for the crazy gasoline formulations.

In my V8 I only use regular gas, occasionally adding RXP to remove cylinder/piston carbon deposits to prevent pre-ignition (I.E.: pinging), and Techron to clean the injectors.

The other huge influence on gas mileage is the speed driven. With the elevated Texas speed limits, my gas mileage has dropped. Every 10 mph cuts 12% in gas mileage. Really enjoy the 75, 80 & 85 mph speed limits though.

 

[ARunner]

That sounds a bit significant for this, but recognize that during the winter the fuel stations sell a winter blend of fuel that nets a little less fuel mileage. Additionally, it's been my experience that when it's cold outside your vehicle takes longer to warm up. Until it's up to operating temperature your fuel mileage will suffer significantly. Therefore, if you're taking a lot of short trips when the temps are low, you'll find the truck rarely warms up to operating temp compared to when it's warmer out, and will therefore suck down a bit more fuel.

 

[Mjtothet]

From 16.5 mpg to 9.5

So, I have a 2004 v8 4x4 4runner and my gas mileage just fell off a cliff

Anyone have any ideas?

Thanks in advance!

 

[ads2539]

In my V8, and regular gas with up to 10% ethanol, I have never gotten mileage over 14-15 mpg. Around town, 11-12 mpg.

I rarely get more than 300 miles out of a tank, unless I’m on a road trip and on the highway most of the time.

 

[andreylights]

So, I have a 2004 v8 4x4 4runner and my gas mileage just fell off a cliff

Anyone have any ideas?

Thanks in advance!

frozen caliper

 

[ravenxm]

if its 90k without plugs it can cause consumtion
also put some fuel cleaner maybe clogged cats

 

[Drak]

I'll second the frozen caliper suggestion.
I've had two freeze on me in six years.
A sudden drop in gas mileage was the first and most obvious clue.
It's pretty easy to spot.
Just go for a drive, then park.
Then walk around the car and put your hand near all four brake pads.
If one is Noticeably Warmer than the other three, you found it.
It will be pretty obvious if this is the case.