2nd gen trd sport 6 speed MPG help!!!

Hello All,

I am new to joining this forum but I have viewed it very often to help with other things. I hope someone can guide me in the correct direction.

I bought my truck used in Feb 2013 with 60k miles. Now im currently at 73k. When i got it I was getting about 18 mpg. Now im between 13-14 mpg!!!! A week or so later after I got it I dropped in a K&N air filter. But I neglected to check the MPG after that. About 2 months ago my check engine light came on. I own a OBD II meter so I plugged it in and ran the code. Basically it came back for a faulty A/F ratio sensor. Since I have the 6cyl I optioned to replace both upper and downstream sensors. I bought them off ebay brand new. They are denso oem same ones I removed from my truck. Than I browsed this forum and read that K&N filters can do more harm than good. So I called the dealer and the recommend that I install a OEM air filter. They said that it should help my fuel consumption problem, because the K&N filter allows to much air in. More air equals more fuel. So i installed the new oem air filter and also disconnected by battery over night to reset the computer. My CEL has remained off but I am still getting 13-14 mpg. Today I cleaned the mass airflow sensor and will see if that makes a difference. I dont run the gears out and always shift around 2k rpm. Basically I drive like grandma and its still horrible on gas. I am running 10w-30 oil and I will change to the 5w recommended oil at my next change. Can anyone please tell me what to check for now? I m at a loss.........

 

I forgot I also changed the spark plugs over the summer so they are new.

 

Keep in mind that the US is now on winter blend gas. You will get less mileage though 13-14 seems to be on the low side for a (assuming) stock truck. I get about 15 with 285/70R17 tires.

 

If you were getting higher MPG before you changed things based on what you said it sounds like you need to return everything to stock. So you have something to compare with I have a 2013 6 speed standard with a 3 inch lift, stock tires and average 23 to 24 mixed driving on Conoco pure gas 89 OCT.

 

Does your truck have a lift kit, oversized tires, all-terrain or mud-terrain tread pattern, or any combination of the above?

 

I'd check ball joints, bearings, and brakes. Alignment would be a quick check for front suspension problems. I get the same mpg out of mine but the way I utilize my truck differs from the norm.

 

Also check to make sure the filter is installed correctly, sometimes with the K&N it fits to tight and you cant close everthing up. if not that or any of the others I would check the plugs. maybe one is difective.

 

Its winter, its cold, your truck takes longer to warm up, and winter gas sucks. Remember to take into account how much you let your truck idle to warm up. Especially when its -15F to -20F here i'll go start my truck 20 mintutes before I leave anywhere and let it warm up.


...

 

^

I can get (rarely, but still...) 13.5-14.5 mpg in winter when temperatures drop to -30C or below. This is with a stock DCSB 6MT 4x4 with winter tires, on winter blend gas with tons of idling.

 

That's a long time to idle. I idle for 30 seconds unless I have to clear my windows

 

They are full of it the stock air filter can flow more air that the engine could ever use. The air filter can not produce more air than the engine needs even if you leave the damn thing out it can't. Snow tires winter blend fuel etc. short trip in the winter particularly if you relay on a scan gauge type of thing for your calculation. Fill the tank get out a pen then see what you get. Mine takes a hit as much as 2 MPG in the winter snow tires longer warm up winter fuel all take a toll mine drop to around 17-18.

 

Oil light goes out I'm gone it warms up much faster doing things than sitting there idling Idling = zero MPG.

 

My 6 speed V6 dropped over 2 mpg when it got cold out. Its pretty normal

 

I'm with you

 

I just keep it under 2000 rpm until the temp guage moves

 

I didnt take into consideration the temp. I live in Calif. so it doesnt get to cold I did notice I went from 16.8 to 16.1 when the weather changed from 60-70 to 40-50 in the morning. so Im sure the more dramatic temp changes will make a bigger difference.

 

Swap the cats, mine went out around 75 k on my 06. Also buy sea foam fuel additive and add to gas tank before adding gas it will clean the fuel filter. Also something else with my 06 is I had to replace my lifters around 80k after having unexplained bad mpg. After that my truck was was good till 155000 where I did a carbon blow out and new MAfS. Things to check.

 

wow replacing the cats?!?!?! thats expensive. not to mention replacing the lifters is expensive to! sounds like I should just trade it in. My truck has 75k on it now and its a 2006. I just think its crazy to replace stuff like that around 75k. is there anyway yo test the cats?

 

I have the same year, engine, transmission, with a K&N CAI with just under 70K miles. I was getting poor MPG (13-14) for a year then I cleaned the MAF and it improved to 17-18 (past 9 months).

 

Thats good news Kyle! I did notice when I removed the MAF sensor is was dirty. I cleaned it up with MAF Sensor cleaner and it was shiny new. I hope this makes a difference but it is to early to tell. I just did it last week and on put 60 miles on the car so far. But ill check at my next fuel up! My next thing is to clean the fuel injectors and a smoke test