Bad gas mileage 2010 4cyl auto 2WD

So I'm Trying hard not to have buyer's remorse on my 2010 Tacoma since one of the main reasons I bought it was the promise of better mileage than I got with my 2001 S-10 with a rompin' stompin' 4.3 pushrod V-6 automatic without any fancy bells and whistles. That truck had tons of power, 5800 lb towing rating, 19.5 mpg year in, year out. Now I'm in this Tacoma 4cyl with much less power, variable valve timing, coil packs, yadda yadda, all kinds of fancy engine management and the same exact configuration, 2wd, access cab, automatic and it's pulling down a big 19mpg. For six tanks of gas now. Changed the plugs and air filter, cleaned the MAF sensor, no change. I understand it's winter and the gas isn't the same mix as summer blend, and I'm doing a lot of short hops but in general it's mixed driving, the same exact routes and usage as I would have done in my ballsy, low tech 19.5 mpg S-10. What am I missing? Otherwise, the truck is great, big improvement in some ways (love the rear doors, self-dimming mirror, super balanced engine/tranny etc). How can that engine be so advanced, supposedly, and return mileage like this? Should I assume it's going to go up considerably when the weather warms up? The S-10 didn't care much at all weather it was winter or summer, so wasn't expecting such radically lower winter mpgs on this one. 88K miles, by the way, seems to run flawlessly, plugs look great. Color me confused.

I guess I should also add I've had at least six jap trucks in the past, none of them got less than 25mpg. Admittedly they had 2.5L engines and were somewhat slower than this, but two of them (datsuns) were 4wd. How is it that added tech can possibly equal worse fuel economy?

 

Sounds right on target to me.

 

At 98k miles my 2010 SR5 Access Cab, 2.7l 4wd, 5sp has delivered 21mpg for all those miles. But, it is running 19-ish during the winter with cold-weather mix fuel, cold starts, long warm-ups.

 

In one of my vehicles, I drop over 6 MPG in the winter VS summer, I figure it's split between the crap winter gas blend, cold weather adding drag thru the driveline and longer warm up cycles that use a lot more fuel to light off and operate the cat converter.

 

This is what I'm talking about. I went way out of my way to avoid a 4wd (2wds are scare around here in Ma) because you're carrying around another 800 lbs of gear--and yet you're getting the same economy in the winter. What gives I wonder.

 

that's encouraging. I'm thinking it'll probably go up about 2 or 3 mpg in the hot weather. Fingers crossed. I'm about to take it on a highway trip, we'll see what that does.

 

19 mpg does sound low, my 4-banger '13 2wd AC regularly averages 26-27 mpg on flat, interstate conditions at 55-60 mph (just under 2000 rpms) during warm weather. I haven't checked in the winter though; probably lower with the winter blends.
I also run my tire psi a little higher (about 36 cold psi all around), and still have the stock Dunlop 215's which may help.
Plus I drive like a grandpa.
https://www.tacomaworld.com/threads...river-rating-system-for-mpg-reporting.361071/

 

So you're THAT guy.

 

Exactly how many MPG were you hoping to get? My 4 cyl access cab 4x4 with 600+ pounds of extra full time gear and 32" load range "E" tires gets 20 mixed city/highway.

I'd expect you to be doing better than you are, but not a hell of a lot better.

Certainly not better enough to justify getting a new truck and going out of your way to avoid 4x4 just in the name of gas mileage.

 

Well it's a four banger, it's not a powerhouse, it's nowhere near as ballsy as the S-10 I had that got over 19, it's light being 2wd. But it is taller and fatter. I was expecting 21-ish in the winter. 22, 23 summer. Just bums me out that with all that technology, and lower power and tow rating I get exactly nothing in return via gas economy. Since everything is computer operated, there's only so much you can do. I might buy a new MAF sensor since I read they don't always calibrate right even after cleaning. Cheap enough at Rockauto. Probably worth a shot. Other than that, no idea.

I already avoided the 4x4, too late for that--but if I'd known this I would have just gotten any one of the 12 4x4s looked at.... And expectations were based on EPA sticker and past experience with Japanese trucks.

 

This is about what I would have expected--slightly better than EPA estimates if driven very conservatively (which is not how I drive though not a lead foot at all), and I'm limping around at the very bottom of the EPA estimate with a mere 160lbs of sand in the back, new tires, low miles... blah blah blah

 

How are you measuring gas mileage OP?

 

odometer miles vs. gallons, is there some other way? No computer on this truck. Stock tires.

 

@earling2 I would actually expect you to be more around 22-25mpg. My '14 4x4 2.7L Automatic got 19.25-21.0 mpg every day it was not towing a trailer. 10 mile commute with a few stop lights and mostly highway traffic at 50-60mph.

Wait until you get a week above 45 degrees and see where your MPGs are then?

 

I would kill to have 22-25.
Warm weather's more or less my plan, though I already ordered a new MAF sensor and a PCV valve for the hell of it.

 

I hope you didn't spend more than a tank of gas on these items. I don't know how many miles you put on a week but the MAF malfunctioning would throw a code. The PCV doesn't always throw a code...

 

The MAF was under $40, the PCV was $4
From what I read on MAFs they can be off without throwing a code. I hosed mine down with MAF cleaner and the lumpy idle went away. Fuel economy stayed the same. Worth a shot. Two second installation.

 

So just following up on this, got my new Walker MAF sensor (cheapest one they had at RockAuto) and PCV, installed them (the old PCV was obviously fine, but what the heck), and went on a 4 hour highway trip. Clocked in at about 23.5 mpg going close to 70 mph the whole way. Then I re-filled and did a bunch of local driving and just calculated 21.5. So, that's pretty much right in the expected ball park, for winter driving. Apparently you can have a bad MAF sensor at 88K miles, even if you just blasted half a can of MAF cleaner in it. so now I love my Tacoma. Happy ending.

 

Maybe you damaged it when cleaning it. They are delicate . Also you don't run a k&n filter do you?

 

No, it's the stock filter. Probably didn't damage it since the reason I cleaned it was bad gas mileage, which remained exactly the same afterwards.