But I'm considering getting rid of my diesel truck and buying a gasser.......
Don't have MUCH need for the big truck anymore and really would like to save on fuel and maintenance costs. Bad thing is I've about got the dang thing paid for......
Have my eye on a Toyota Tundra. Still have to have 4wd for the hunting lease and 4 full doors. Probably not the crew max but the regular crew cab.
Thoughts on this truck?

My youngest son has a Tundra 4wd, which is a fine truck, and my oldest came out of a Z-71 and went to an Eco-Boost 4wd and it is a fine truck also. Both are great trucks. If I were to come out of my Ram 4wd Diesel, I would probably go to the Toy over the Eco-Boost, just because I think the truck is built better. That said, the Eco-Boost gets way, way, way, better fuel mileage. My Diesel gets better mileage than the Toy, and is comparable to the Eco-boost, but today on the way into work, gas was $1.79 for no lead and $2.09 for diesel. When you are talking comparable fuel comsumption between the eco-boost and the diesel, it's a no brainer. Go to the Eco-Boost. The price of fuel probably makes up for the poor fuel mileage in the Tundra and it will probably last every bit as long as the diesel if you decide to keep it.

I'm not sure the Tundra ever saved anybody on fuel costs. There are more efficient trucks, if that a concern. With that said, Toyota makes a really nice truck.

If your trading into a gasser to save money on fuel the tundra would be at the bottom of my list.

I would look at the rides offering the best fuel mileage depending on what your needs are, fuel is only going to go up in the future. I would look at ram ecodiesel, Ford ecoboosts(whichever suits your needs the 2.7 or 3.5) or maybe even a GM canyon/Colorado with the diesel. Its nice to be able to drive a truck that gets the same fuel mileage as cars from a few years ago.

Full size 4wd is a must. Bigger payload and tow capacity the better. I'm not completely sold on the Eco boost but haven't ruled it out. After I started thinking about it I remembered people complaining about the Tundras's poor mileage.
I'm not buying new so I have to get best truck with better mileage for say between 2010-2013 trucks.

Been there done that! Went from diesel back to gas and a year later was missing the diesel so bad I traded back into a diesel. Nothing like the torque of a big Cummins.

A diesel is the only way to go if you are going to work it.But if you are going to use a diesel for a daily driver it will cost you in the long run.

Working a diesel is a fairly relative term. I'm pretty certain towing a 2000lb fishing rig isn't working a truck rated for well into the tens of thousands of pounds. It's not even a daily driver as my truck sits until I go fishing or decide to run into town for something. I have a work vehicle so don't drive the truck too much.
I know that NOT working the diesel is not good for it which adds to future maintenance in the long run. Hence one of my main reasons for getting out of it. Will I miss the power? Sure as heck I will but the fact it won't even be my primary tow vehicle or family vehicle for towing the RV negates all that.
Family dynamics have changed and with the next child on the way ALL of my RVing is now with the 'burb and my fishing vehicle is a very expensive piece of machinery that costs a lot just sitting.
On another note, I've talked to a few buddies who have had an eco boost and they absolutely love them. Fuel mileage is good, not as high as some claim but way better than some alternatives. So leaning that way by way of more research.

Hemi rocks - pulls anything and throttle response is smooth. Put bags in the rear coils - you get a really nice ride and the rear end won't sag. I got great service from mine.

Love my ecoboost, too. Can't beat it as a tow engine. I really think if you can find a used 2015 2.7l, it would fit your needs and get excellent economy. The Fords are reliable.

I'm looking in the 2011-2012 range. I do tow heavier trailers on occasion so I won't go less than the 3.5l when it comes down to it. More and more people I talk to love the ecoboost. It's not a diesel by any means but they compare to them in the usable power band.

Yeah, it doesn't run like a typical gasser. It pulls hard at low rpms.

According to fuelly.com a 2012 f 150 EcoBoost averages 15.4 miles a gallon and a 2012 Tundra with the 5.7 averaged 14.2 miles per gallon.
A properly equipt f150 Will have a max tow capacity advantage, but the tundra will have a mechanical advantage through the first 4 gears due to the 4.30 rear end.

On a side note, I walked away from an ecoboost f150 last week. At a 1/4 mile I was up a truck and a half. I was very very surprised... the tundra isn't the slouch the ecoboost fanboy want it to be.

My advise: go buy the one you like the most.

Again you're overlooking the transmission gearing. The tundra has an advantage at high rpms. Tow with the Ford, you'll fall in love.

Heres the math on peak TQ at the rear wheels in each gear

Tundra with 5.7 w/4.30rear VS F150 with 3.5eco w/3.55rear

1st gear(ft/lbs): Tundra= 5742 F150=6217
2nd gear(ft/lbs : Tundra= 3380 F150=3489
3rd gear(ft/lbs): Tundra= 2328 F150=2266
4th gear(ft/lbs): Tundra= 1724 F150=1700
5th gear(ft/lbs): Tundra= 1259 F150=1282
6th gear(ft/lbs): Tundra= 1017 F150=1029

I've towed with a ecoboost, It's great, but a Tundra tows just as nice, albeit @ a higher RPM