Gas mileage problems with 06 Tacoma V6

I have a 2006 Tacoma Access Cab v6 4wd 6 speed manual and a few months ago I got a dual exhaust magno flow put on my truck hoping to get better gas mileage, but instead I am getting worse gas mileage now. I also have a K&N cold air intake. Before I put any of those on I was getting around 310 miles on a tank. Now I am averaging around 260 a tank. I was mainly wondering why this is happening and if its time to change the spark plugs out or get a tune up, I just hit 71,000 miles. Or mainly if theres anything I need to do to keep my truck running good. Appreciate any tips, thanks.

 

You're on the pipe too much. Lay off the loud pedal

 

X2

 

Spark plugs should be changed every 20-25 thousand miles. http://www.tacomaworld.com/forum/technical-chat/30479-how-spark-plug-change-1-gr-fe.html

I don't have any experience with k&n intake systems, but I heard they wont do much or anything for hp gains or MPG's for 2nd Gen trucks.

A exhaust system will also just about do nothing for hp and MPG's, the only thing it will just about do is make your truck sound better. They do a lot for older cars, but modern cars...not so much.

Change the plugs, see if that helps, also run some injector clearer through, clean the MAF senor, clean the throttle body. If that doesn't do the trick, then you may want to try putting on your old air intake and or exhaust.

 

Haha, trust me Ive tried driving slow and easy for a couple of full tanks and still no difference...

 

Not slowin down. Its when ya shift. No more than 2k rpm. I gained almost 2 mpg just by doin that

 

Thanks bakotruck for the info. I will definetly look into that, I just recently got out of the marines, used to be stationed in 29 palms, CA and now im back in georgia and I was just wondering if elevation factors with the air difference could be affecting this also?

 

Ok Ill try that also, I usually go close to 3k

 

Intakes and exhaust simply don't increase mpg.

More air needs more gas to make more power, but not using more power doesn't use less gas than stock.

http://www.fuelsaving.info/power_economy.htm

Higher altitude usually means better mpg. Thinner air means lower wind resistence along with less power.

 

there's your problem lol, seriously keep it under 2k and i think youll see a difference...

 

I think so. Last Summer we were out in AZ and we were looking at buying a used Jeep to put behind the RV but my uncle said it wasnt a good idea because something with the throttle body and the intake due to the elevation and thickness/thinness of the air

 

Cleaning your throttle body can help with gas mileage

http://www.tacomaworld.com/forum/technical-chat/50153-how-cleaning-throttle-body.html

 

Alright awesome , appreciate the info.. one more thing.. what would be the best air pressure for 265/75/16 tires?

 

I would bet the duals are hurting, these engines need stock backpressure for scavenging effects.

 

I was thinking that also, my brother who works for lockheed being an aero. engineer or some crap like that was trying to explain to me the same thing what your saying.

 

I would think if changing the exhaust would make gas mileage go up, then the engineers at Toyota would have done that before the truck went to the dealer to be sold.

I think that if you want to increase performance or mileage on a late model vehicle, then it needs to be a package deal. Change the exhaust for more airflow, then have to change the intake as well, change the intake, now you need head work and new camshafts, new programming for the computer, etc.

Not against modding a vehicle, but I have done small things in the past and it usually doesn't pay off for me in terms of cost of operation. All I would expect from an exhaust is a different sound.

 

I can second the below 2K rpm shifts. Makes a big difference for me. It's a boring way to drive though.

 

Changing the exhaust to the dual system changed the back pressure. It most likely improved power at the expense of gas milage. Most add on mods are usually for power not gas milage as I think you are finding out. Todays vehicles are factory tuned for the best gas milage they can get to meet state and federal regulations. Several years ago one of the GM divisions I think was Pontiac tried every gas savings devices on the market and they found they had very little or no impact on gas milage and often decreased the gas milage. For more power there are lots of things you can do but at the expense of gas milage.