Mileage drop to 12 and lower
06-20-2011, 05:08 PM
#51
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gas mileage
I have a 06 FX4 5.4 with 65,000 miles. The gas mileage has dropped to 12mpg and lower. I have a edge chip and usually get 15mpg and better. When I take the chip off it has a bad bog too. I changed the fuel filter, cleaned the air filter and cleaned the mas air flow sensor. Anyone else had this problem or know what I could do next. Thanks
01-05-2013, 01:50 PM
#52
Senior Member
Wow that is incredible. Do you really think that can be completely attributed to the Amsoil?
12-20-2014, 02:15 PM
#53
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12-21-2014, 08:38 PM
#54
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Going back to the plugs... I've seen videos of ford techs that say using an impact gun to remove the plugs is the only way to go if you don't want them to break... It seems like it makes sense because the impact really shocks them out instead of slowly torquing them out, giving them more of a chance to separate... Anyone else seen or tried this technique? I think I'm going to change my plugs once a year, just to be safe...
12-22-2014, 06:18 PM
#55
Senior Member
Last fall I noticed a sudden drop in fuel economy. 14.5mpg one tank, 12mpg the next, 8.5mpg the next tank. Took it into the dealer and their diagnostics showed one set of valves was running rich. Ended up getting new rocker arms and cam phasers, along with spark plugs. Good thing I had an extended warranty. Back up to 14.5-15 mpg/city on winter gas. If you're down under 10 mpg I'd consider having your mechanic hook it up to his diag. computer.
That is a nice warranty perk................
Pays off for sure
01-06-2015, 06:35 PM
#57
Member
Wanted to chime in. Colorado resident here in the Mile High (hiiiiigh) club haha. 05 Lariat 4x4, almost entirely stock. Winter months depends on driving conditions. Denver can be a real bia. My morning commute beats rushhour and I can average 12.9-14.6 in city with 15.6 to 17.8 highway (this is winter driving). However, when I hit rush hour in the evening I am lucky to average 11.5mpg.
Maybe a mixture of cold air and a few mechanical issues are giving you a hard time? I heard one of the first problems you begin to experience with VCT solenoid/phaser problems is a noticeable decrease in HP and MPG as the engine attempts to adjust... So the people having the issue, are you noticing anything else?
Might also be time to check your fuel filter because some stations pump some pretty nasty gas. If it were me I'd do what others suggested and pull some plugs to see if there are any signs of old/damaged plugs and any oil or moisture on them. I am at 169,000 miles and I keep on going strong.
Maybe a mixture of cold air and a few mechanical issues are giving you a hard time? I heard one of the first problems you begin to experience with VCT solenoid/phaser problems is a noticeable decrease in HP and MPG as the engine attempts to adjust... So the people having the issue, are you noticing anything else?
Might also be time to check your fuel filter because some stations pump some pretty nasty gas. If it were me I'd do what others suggested and pull some plugs to see if there are any signs of old/damaged plugs and any oil or moisture on them. I am at 169,000 miles and I keep on going strong.
02-18-2015, 09:16 AM
#59
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Mine went up a bit with change of fluids
I have a 06 2wd Screw-6.5ft bed with 5.4L. I've been using Mobil 1 AFE 0W-20, along with Mobil 1 ATF change and Mobil 1 gear lube in rear axle. Driving on mostly highway/some city I've been getting 14.1-15.1mpg-depends on temps and my right foot. In warmer weather w/o A/C on-I can get 15-16mpg consistently. I have found best gas mileage is running between 60-65mph on highway, outside temps around 50-60 degrees. I've gotten as high as 20mpg, but only a few times. I also have 3.73 limited slip axle.
I tow a 5000lb travel trailer in summer, and mileage ranges from 9.0-12mpg. Lower mileage is with a headwind & A/C, only go 60mph when towing. I got a ScanGauge II several years ago, and this helps me with watching my right foot and engine load.
I find 18-20 mpg with 4wd a bit optimistic, don't know anyone else getting close to this on a 4wd.
I tow a 5000lb travel trailer in summer, and mileage ranges from 9.0-12mpg. Lower mileage is with a headwind & A/C, only go 60mph when towing. I got a ScanGauge II several years ago, and this helps me with watching my right foot and engine load.
I find 18-20 mpg with 4wd a bit optimistic, don't know anyone else getting close to this on a 4wd.
Last edited by FrozenTundraGuy; 02-18-2015 at 09:19 AM. Reason: Spelling error