MPG worse after tuneup

I checked my mpg when I first got the truck last March, On the highway I was getting 19.
I figured that was pretty decent being the truck is not aerodynamic at all. And it has 20"
rims and big wide tires on it. Which creates wind drag. Mt last car was a 2001 Nissan Altima
and it got 20 mpg. So for a truck with twice the engine size and horsepower I think 19
is good. Plus my commute is very short only 6 miles round trip.
I just got a new set of NGK spark plugs to put in it soon. So that might help get to 20 mpg.

 

The TB cleaning is not your problem. That was 15K ago. One of 2 things:

- Your tune-up was a tune-down
- Texas has winter gas and maybe the winter gas trucks showed up recently in your area. Because Tx winters pale in comparison to ND/MI/etc. maybe that blend isn't shipped until later in the season? Hell if I know.

 

https://www.fueleconomy.gov/feg/coldweather.shtml

 

Unhooking your battery will reset it right there, that's why. You could have just disconnected it for 15 minutes and done nothing to the truck but reconnect it and you'd see the same result.

Your ECU has to relearn..usually about 100 miles driven or so. Once you hit that I think you'll see it return to normal.

 

I've cleaned a few MAFs and have never had to pull battery ground strap - wait xx mins - reconnect - then drive xx miles.

I clean the MAF with MAF cleaner - both(2) of the "wired" sections of the MAF - let it air dry - reconnect and drive off w/o incident.

I can't help but wonder if people are cleaning their MAFs with the wrong product...IE...alcohol/carb cleaner?

 

Agree,give it a week or so.

 

https://www.caranddriver.com/news/a15339380/the-vapor-rub-summer-versus-winter-gasoline-explained/

This discusses the difference it all has to do with emissions and "Reid vapor pressure" of the gasoline.

https://www.epa.gov/gasoline-standards/gasoline-reid-vapor-pressure

 

Perhaps it would be more pronounced in a place like MA versus Texas but it's still a thing

 

Yes absolutely, the gasoline is blended by region.

 

I’ve done the same thing, watched the tutorials, and yes, only use MAF cleaner......
Winter fuel change to the week of the tuneup, too much of a coincidence.
It’s been 400 miles driven
Will look at TB to see how dirty this weekend.....

 

Well, i had a good laugh at “winter gas” til someone else said it and i thought to look it up. Learned something new today. Guess coming from California theres some cold weather experiences i just haven’t had.

 

I've noticed this in TX. I usually fill up 18 gallons and get 380-420 miles. As of a week or two ago I've only been able to get about 320-360 miles.

I did notice a dramatic change with spark plugs and URD Spec U headers though which were installed two weeks ago. Maybe a correlation of sorts.

 

Dang, 380-420 miles. I only get 220-230 miles in my truck now. Miss those days of better gas mileage.

 

Do what I did, lift it, throw some bigger tires on it and drive with a heavy foot and then you’ll expect to get shitty mpg’s...problem solved!!

 

Add a few more psi to your tires, perhaps?

 

I mostly only drive highway. Being here in Texas there's alot of it. I stick it in cruise control going 65-70 and drive like a granny nowadays. It takes me an hour to hit the posted speed limit of 40 in the city

 

To get the best gas mileage with these trucks, that's the way you have to drive. Every Toyota I've owned(except the 76 Landcruiser) has had an MPG decline about 60mph.

 

The problem is the winter blend gas. To offset the affects you must change out the summer air in yaw tires to winter air.
This will balance out the truck.
It works . . .

 

Yep, even inching close to 70 kills alot of gas! I used to cruise at higher speeds until I realized Im not saving much time or gas speeding everywhere.

 

Unfortunately, the one piece of road I have to drive between Houston and Dallas, I45, speed limit is 75 and folks are doing 80 in the slow lane......the semi trucks
Not unusual to get passed by some Ford F-250 doing 100.