Sudden 4mpg drop

I hate to ask this, but before I start looking into the usual suspects, I wanted to ask if anyone else has seen this?

I searched and nothing comes up that is vague like my issue. It's always tires and lift issues.

Over the my last 2 tanks of gas, I have gone from 11/12mpg to 8.
No change in driving habits.
No mods to the truck.
Lift a few months ago took me from 12/13 to 11/12 mixed driving.

No check engine lights, no strange behavior from the truck whatsoever, all seems fine, but I lost 3-4mpg over 2 tanks out of the blue.
Confirmed with fuely app, and the dash reading.

Any known issues to look at before I check airfilter, maf, and plugs /coils?

I always get mystery issues like this. Never the easy check engine light shit for me lol.

 

If you went to bigger tires are you accounting for that in the MPG calculations, or are you just going off the dash?

 

Last time I had this issue (on my 4Runner) it was a bad O2 sensor; had no lights pop on or any of that stuff.

 

As I said, no changes to the truck since my bilstein lift a few months ago, which took me from 12/13mpg to 11/12 mpg mixed driving. This drop in mgp is in the last 2-3 weeks.

Tires where new in Feb when I bought truck. 275/55/20 Yoko AT crap. Truck is 2014 1794. No engine mods trd exhaust since new first owner installed. I'm 2nd owner.

 

Good idea, forgot about those, thanks!

Absurd you don't get cel's for things like those, or extreme mpg drops.

 

It’s cause your truck is WHITE, so it’s super fast!

 

Drive around for a bit and check to see if one of your wheels has a locked up brake caliper.

Edit: it will be really hot.

 

Your dam right!

And nice and cool inside and out to!

 

Anther good idea, thanks!

Will use my infrared temp gun on that.

But I would be surprised by this, usually get burnt brake smell when this happens and it's usually noticeable when coasting.

At least on smaller vehicles it has been.

 

When is the last time you spray cleaned your MAF and throttle body?
Is the air filter clean?

 

You been eating too many krispy kremes lately? Payload can drag the mpg down

 

Ah, the hazards of skimming. There were a couple good suggestions, but I'd lean more toward the sensor issues.

 

Fuel filter? Maybe bad wheel bearing? Although I’d think you’d hear that.

 

Is that hand calculated?

 

Usually my experience as well. I’ve had about 4 of them lock up on work trucks over the years and it’s fairly obvious most of the time.

 

Never.

Bought truck in Feb/March, 54k miles.
Just rolled over 60k miles last week.

I did check air filter before beach trip in June, it was like new, air box was clean also.

This is on my list to do, as part of the diagnostics when I get a chance to go outside and sweat to death looking into the issue.
Would be surprised if its very dirty, but certainly can't hurt to clean it.

You know what.......
I just realized I have been lying to you all
I did change something a few weeks ago......
Added the Mycar phone app to the Fortin remote start.

I probably have been using it a lot more now, but dam, 4mpg loss?
I can almost watch the fuel gauge dropping when I drive now.
I've gone about 125 miles on this 2nd low mpg tank from full, and i'm already at under 1/2 tank, been driving even more gently than normal (hard to do for sure!)
No towing, AC on nonstop, same as since before June.
Hell I got better MPG the entire OBX trip in June with 4 adults, 135lbs, 145lbs, 250lbs, and 300+lbs, plus bed full of 2 coolers of food/drink, luggage and beach gear, with driving on the beach 3 days in a row for 4-6 hours each day lol.

Could it really be from over using the remote start?
Id say I use it 1-3 times a day, every other day (mostly working from home but go into the office 2-3 times a week since last week)

If its from using the remote start, thats crazy how much it affects mpgs!

 

From my first post guys.....

 

My mileage goes to shit every winter from idling more. So, possible.

 

I would bet money that's it. Idle time makes the computers read 0 MPG and it will screw your computer numbers. If you are letting it idle to warm up or cool down, the computer is going to show huge losses in MPG, but you are actually doing much better than that.

 

Yup, I agree.

Still worth ruling out for sure, better safe than sorry.
This is going to be a pita to figure out.

I really do always get the strange problems lmao.

 

Mileage has been consistent since purchase in Feb/March.

Until I did Bilstein 3in front and CB 1.75in rear lift end of May, or beginning of June, I forget.

Was getting 12/13mpg, after lift I was getting 11/12mpg mixed driving same stuff each week.
This seems normal for doing a lift, keeping same wheels and tires, which I did.

 

been running the a/c quite a bit?

 

I would agree, thank you.

But, the Fuely app which I have been using every fill up since I bought the truck, shows previous tank 8 mpg. And this tank the dash is showing about the same.
This is how I noticed it, last fill up Fuely said 8mpg, I said WTF, and double checked it and re did it, and its still 8mpg.

Truck dash is almost the same figure, very close, and well below what it normally reads.

I would certainly expect some mpg loss from using remote start alot, but dam, 4mpg, that just seems way excessive to me.
Even my old turbo 4cyl 550hp Mitsubishi Eclipse GST with 750 injectors did not eat that much gas from remote start and turbo timer cool downs.

Next tank I will not use remote start at all and see what happens, gonna be hard to remember not to do that, it's hot and humid as fucking hell here with more to come so sayeth the lying weathermen lol.

 

Per my previous posts, yes, nonstop since before june, every time I drive.

I sweat like a stuck pig at any temp over 70 degrees, while just standing still lol.

 

LOL

Sorry, but this is slightly comical.

Really shows how little reading gets done prior to replies/comments.

 

I don't think you understand. There are no "conical" parts that would relate to his lost MPGs after lowering his truck and installing a supercharger.

 

Good thought!

Nope, mine is absolutely non-flex fuel.
I know all about ethanol trash, I avoid it like the plague it is.

I made sure to buy a real gas truck when I was searching for my baby.

Interesting side note, my brother spent an extra $2500 on his $15k built motor replacement in his Subbie STI for optional straight Ethanol running.
He just doesn't get it, even after I showed him all the research.
Waste of money for the mods, and on the fuel every time he runs it.
Its a DD car, so no real benefit to the higher HP when he's on Ethanol, he's not on a race track needing all its got.

Anyway, where's my 4mpg?
I lost it on the highway a couple weeks ago, if anyone finds it, please send it home, we are worried sick!

 

Agreed.

But I don't really mind to much, gives me reasons to post and get my count up