2nd Gen MPG Issues

So I've had my 2015 DCSB V6 RWD for about a little over a year now. When I first bought it, I was getting relatively okay (for a truck) fuel economy, like 280-300 miles per tank. Over my year of ownership, I've done a few mods but nothing extremely crazy. However my range has gone from around 300 miles per tank to lucky to break 210 miles per tank, with more of an average around 190 miles. I've installed the TRD cat back exhaust, 2.5" Bilstein 5100s, 3rd Gen "TRD Pro" wheels and 265/70/R17 BFG K02's. Am I just stupid or would this all really affect my fuel economy to this extreme? I've seen threads where people have similar issues, and I also have a few friends with 2nd gen's that are way more modded than mine and get better fuel economy than mine. Any of y'all have any ideas of what could be going on? I haven't noticed any decrease in power or performance. The truck seems to be running completely fine. This is the first Tacoma I've owned so I'm not incredibly familiar with their powertrains.

 

A lift and tires definitely hits MPG.

More wind resistance more drag.

Also keep in mind larger tires change your odometer reading so you may be getting slightly better than you think if you're not calculating for the differential there.

Also winter blend gas right now.

Your cat back won't add anything but noise without upstream exhaust mods.

As for guys with more mods getting better MPG than you two likelihoods:

They have other supporting mods that help and they drive differently than you.

or

They're lying.

 

Here ya go. If you got bigger tires than stock just get the difference and add it to your tripometer then divide by how many gallons you filled up by.

 

Bone stock, these trucks are bricks trying to cut through the wind. Anything that makes it even harder to cut through the wind is going to be felt.

How fast do you go on the highway? I basically don't exceed 70 anymore in my Tacoma after I did some MPG testing.

 

I appreciate the info. I figured it was the ladder but I just wanted to make sure.

 

Most of my driving is done in the city in mostly stop and go traffic, and I don't normally exceed 60 on an average day. On the highways, I normally maintain 70-75.

 

Keep it 70 or below and drive like a grandpa. Combined driving I still get 300+ per tank on average. I also run 265/70/17 and set it at 68-70 on highways always with cruise control. Anything higher and my MPGs plummet like a rock. I log every fillup & trip in my own Excel file as empirical data (see here and here). Other forum posts should back up the same conclusion.

As others have said the lift also affects it. Wind resistance is no joke.

If your BFG KO2s are E load range my data also suggests to expect about 2 MPGs loss just for tires (I also had them at first, now run Grabber GTX C load).

Ambient temperatures: I find when it's below 20°F my mileage goes down regardless of everything else. Summer I can get 21MPG per tank, Wisconsin winters are more like 17-18MPG per tank.

Maintaining things like wheel bearings, alignment, suspension, can have an effect. Cleaning your MAF/throttle body is another common root cause. All simple things to check first.

 

That will kill mpg, as well as speeds above 70mph.

Also, make sure you correct for increase tire size, also miles per tank is not an accurate way to test because you never fill up the same amount. Proper way, fill tank fully, reset ODO, drive, fill up. Note gas needed. Take miles drive x correction factor / gas needed to fill up.

 

A very risky "life hack" for Tacoma MPG would be to drive 70mph everywhere to optimize efficiency. Cops and most sane people will get very angry at you though, so keep that in mind. You might also lose your license if you do it in certain areas, like near active school zones.

 

210 per tank have someone check the fuel trims. I have 285/70/17 and my combined is about 320 per tank. That’s driving posted speed limits.

 

The Tacoma has a 21 gallon fuel tank.
On E you should have about 2.5-3 gallons left in the tank.

Let us assume you are saying that you fill to full. Then drive to E. Let’s be generous and say you only used 18 gallons. Let’s say you went 200 miles on that tank. That is 11.11 mpg. That is definitely low.

So what does this all mean?
Absolutely NOTHING, because you need to calculate MPG just a @nd4spdbh said above.