5th Generation Poor Fuel Efficiency Causes?

[bloodninja]

hello everyone, im new to the forum. Im having an issue with the MPG on my 5th gen 2014 4runner limited brand new with only 14,000 miles on it. when my parents first purchased it it was giving us the average Mpg stated, but now if i do use the dash MPG display it has gone significantly down. it went from 19 mpg down to 11, as it states, and its been going down since, and i have noticed that my gas doesnt last as log as it used to. i live in chicago, i use BP midgrade to the best grade gas. im upset that its giving me really bad gas mileage. if anyone can help me with this issue i would greatly appreciate it, i feel this forum is the best place for me to ask this question. Can anyone help me with this issue? i would very much appreciate it. Its also completely stock btw

1) You alluded to it being driven by your parents prior to you being the primary driver. You're comparing apples and oranges. Rarely do younger people (yes, I'm making that inference) drive in the same manner as their parents. It's likely that they either took trips with more highway time than you, or drove in a much less enthusiastic manner.

2) Like me, you live in a major city. I'm assuming much of your daily drives are heavily stop and go (stop signs, poorly timed traffic lights). That has a huge impact on fuel efficiency as you're constantly stopping the momentum you've generated.


Tips:
1) Don't take fuel economy comparisons with other people as the gospel. Everybody's situation is a bit different.

2) Accelerate more slowly. The longer the Eco light stays on while accelerating, the (generally) better your efficiency will be. It's just an indicator based on throttle position/load (so it seems), but still useful for learning how the T4R operates.

3) Stop using midgrade or high grade fuel unless you have a scientifically backed reason to do so. You're throwing your money to the wind. The T4R is designed to operate on 87 octane.


For a general comparison (again, do not read too much into this), I've gotten as low as 12 MPG (driving like an idiot) and as high as 25 (back when it was stock and I drove 50 MPH for a few hundred miles without hitting a single stopping point)


Sent from my Pixel using Tapatalk

 

[Ray Dunakin]

"5th Generation Poor Fuel Efficiency Causes?"


The #1 cause is driving it.

 

[Car Nut]

The Tundra only gets 11-13 MPG so anything over 16 MPG would be great. hwell:

 

[eddyrunner]

i dont drive very fast at all. only highway speeds on the highway, my mother drives it and i drive it and we have both seen the gas mileage go down significantly. well im honestly comparing my full mileage to what toyota sold me on what was the average MPG for city and highway. its throttle also lacks power for some reason on the highways. my trips are usually tops 15 minute drives. so for me to lose almost a quarter tank just driving for that little is what has made me upset.

 

[Fidgets]

Winter fuel mix might have an impact vs non-winter fuel mix

Short drives like 15 min are terrible for mpg

Slow down

Check tire pressure

Slow down

Replace air filter if needed

Slow down

Maybe add some fuel system cleaner (Chevron, Redline for example)

Slow down

 

[vorwac00]

Onset of poor gas Mileage

So, I have owned two T4R's, both bought brand new.

First was a 1998 (in wreck at 85,000), and the second IS a 2012 (currently with 93,000)

Both were very well maintained, always synthetic per manual every 6000 miles. All grease nipples were hit every oil change.

1998 never had the transfer case or diff's oil changed. Brakes done by Toyota
2012 transfer case and diffs done at 50,000. Brakes done by me.

All had consistent tire pressures.

The 1998 went from around 15 to 10 mpg over a period of 6 months and never recovered at about 70,000 miles (unless you call the accident a recovery).

The 2012 is currently exhibiting that same slide, and I have no idea how to fix.... and neither does Toyota.

I know these are sealed wheel bearings, but can they go bad?

 

[Jivewalker]

I know these are sealed wheel bearings, but can they go bad?

Yes, they can go bad. I just replaced my fronts but it had no effect on the constant 18.5mpg I get. I think the rears may need it soon as well. I'm at 180k miles. I've got 18.5 for as long as I can remember.

 

[83Mule]

Check the Thermostat?......perhaps it is stuck open or partially and engine is not running in closed loop= too rich and bad mpg.

 

[Lester Lugnut]

I would pull and clean the Mass Air flow Sensor - known as MAF sensor. Did not see it in pages 1-4 - maybe I missed it.

This device does not need to be deteriorate enough to throw a code before it causes MPG to suffer.

If not handled already - consider new air filter. Some may not agree as your vehicle has only 15000 miles, but age also comes into play. Your 4R is 6 yrs. old.

Update - I wanted to include a parts sketch of where the MAF sensor is located on the 5th Gen 4R - #22204 in pic - air filter housing - upper part of pic

 

[Jetboy]

So, I have owned two T4R's, both bought brand new.

First was a 1998 (in wreck at 85,000), and the second IS a 2012 (currently with 93,000)

Both were very well maintained, always synthetic per manual every 6000 miles. All grease nipples were hit every oil change.

1998 never had the transfer case or diff's oil changed. Brakes done by Toyota
2012 transfer case and diffs done at 50,000. Brakes done by me.

All had consistent tire pressures.

The 1998 went from around 15 to 10 mpg over a period of 6 months and never recovered at about 70,000 miles (unless you call the accident a recovery).

The 2012 is currently exhibiting that same slide, and I have no idea how to fix.... and neither does Toyota.

I know these are sealed wheel bearings, but can they go bad?

If a dealer did the diffs and transfer case - it's all but guaranteed they used non-synthetic fluids to refill. Toyota uses synthetic gear lubes in all the cases. So you're going to lose some mpg from that, but probably not a lot. Maybe 1mpg.

Do you have an lift, level kit, or aftermarket roof rack? Or even a bug deflector? All of those will hurt your highway mileage. GM did a pretty good study a while back that showed that a bug deflector alone will cost about 1mpg.

The common issue on the 5vz (your 3rd gen 4R) was the O2 sensors. They could essentially wear out, but you wouldn't know because the engine wouldn't identify them as having an issue. So over time they'd slowly cause a slight rich burn condition and fuel mileage would drop. I considered it sort of like preventative maintenance on my 1996. I changed them at 150 and 200k miles. Both times I had a noticeable bump up in fuel economy after.

Those are the big ones I can think of. I don't think I'm aware of any O2 sensor issues on the 5th gens though.

The wheel bearings usually start making a lot of nose is how you know they're bad. Not from anything mpg related. If they were causing excessive drag, they'd overheat and fail pretty fast. They don't have a lot of cooling ability and the thermal runaway happens pretty quick if something goes wrong that increases friction a lot.

The one thing that can cause excess drag and you may not notice is a seized brake caliper or parking brake. After you drive next time put your hand on the wheels. The brakes will probably be kinda hot, so don't burn yourself, but feel if you can for any one of the wheels being a lot hotter than the others. That would suggest a frozen brake caliper.

Could also be your driving - style or the nature of your driving. Lots of city driving of course is going to reduce mpg. Driving north of about 90mph really kills the mpg too. The next time you're on an open stretch of highway on flat ground, reset the mpg calculator and see what it gets at 65mph. For a stock 4Runner you should get around 21mpg.

Finally - double check that your tires are inflated properly.

Those are all the ideas I know of.

Good luck.

 

[4Rman]

Hello,

I have a 2013 SR5 7 passenger with 15,000 miles (23,000km) on it. I am a retired pro race driver and broke the engine in properly and have kept the service up to date. I always use name brand gas.

I drive 85% Highway and 15% city @ 70 mph and 35 mph respectively. My daily commute is FLAT along a ocean over a large river delta and I do not start fast from the light. (ECO is green 95+% time)

When new 1 year ago I was getting 19 MPG on this type of driving... now I am at 14.6 mpg!!! No 4wd, no snow, no trip into mountains. Toyota service does not want to even look at this.

I have reset the ECU back to factory specs before this last fill up.. and no change.

OOO Wise and long time members (that may work as a toyota tech,) what could go wrong mechanically in this to cause the MPG to drop like that?

Burns not a drop of oil. I am perplexed... could it be a bad O2 sensor???

Looking for more ideas before I present my problems more formally to service.

Thanks for reading and your help.

(The funny thing is that I will most likely do a lift and some other mods that will make the issue worse... but if I am already at 14 MPG where will I end up??? Lambo LM002 territory?)

I scanned through the whole thread and did not see any mention of "engine oil". Did your MPG started going down after the 10K oil change? If so, is it possible that one of the "kids" working in the quick lube at Toyota put non-synthetic oil or did they forget to replace the oil filter? Now you are at 15K, and if it is not synthetic it is probably in need of an oil change. Check it.

 

[vorwac00]

I appreciate all the feedback regarding the fuel mileage drop on both my T4R's. Regarding the transfer case and diffs... I did them myself using synthetic. The mileage drop came well after that change. I like the ideas regarding the O2 sensor and the dragging caliper. I will investigate those areas ASAP.

I thought it was funny when I went to the dealer for the specified Toyota 75wLF for the transfer case... they had none. Service mgr told me to simply use Mobil 1 75w-90 gear oil as that's what they use.

By the way (hijack), when the Toyota dealer quotes a brake job, they quote their Toyota low end pads that are NOT OEM. When I asked for the pads that the car originally came with (to install myself), they indicated they would have to order them. The cheap pads are exactly that... cheap. A ex-Toyota mechanic confirmed to me the cheap pads wear poorly, lots of brake dust, and squeal. Sigh...

 

[TeaMan]

This is a great thread. A lot of great information.

I have a 2020 Offroad Premium and am having what I'd call extreme poor mileage. I do have some modifications that I suspect are contributing, but they should not at the level that I'm seeing. I have a 2" leveling kit in the front and 285/70R17's KO2's. I also have a bug deflector. I do need to install a 1" body lift to stop my tires from rubbing on a sharp turn in reverse. This won't help, but do want to keep the look and like the performance of the tires. I have less than 1000 miles on it, it's still breaking in also, but still seems extreme.

My mileage is better in town/city than on the highway which is a bit confusing. I actually see the mileage in the city to be around 17MPG average and Highway drop to lower 14MPG's. Also if I drive in the 75 to 80 MPH area it drops to high 13's.

So far, I like the vehicle. It's my first, I traded a Tacoma for it. Not impressed with the power, but it does get me where I need to go.

Wondering if anyone else is seeing anything like this with the 2020.

Thanks.

 

[Bigbugberg]

Gas comparison

I have a 2017 TDORP and a 2017 F150 Ecoboost. I find it really sad that my F150 gets better gas mileage. The f150 weighs 1000lbs more, is taller, has 100+ more horsepower, is waaaay faster, tows more, trans runs cooler towing, and gets better mileage. Toyota should be ashamed. Back in the 70's Toyota was the answer to gas guzzling american land yachts. How the tables have turned...

 

[Sky]

I have a 2017 TDORP and a 2017 F150 Ecoboost. I find it really sad that my F150 gets better gas mileage. The f150 weighs 1000lbs more, is taller, has 100+ more horsepower, is waaaay faster, tows more, trans runs cooler towing, and gets better mileage. Toyota should be ashamed. Back in the 70's Toyota was the answer to gas guzzling american land yachts. How the tables have turned...

Not surprising- the EcoBoost is turbocharged- one of Ford's big claims when they came out was how it was more powerful AND more fuel efficient.
You may also have the 10 speed trans on the F150- compared to just 5 on 4R.

 

[ToolUser1]

Parking brake shoes

Just another idea to consider if your mileage has dropped - check the temp on the parking brake drums. I did a rear brake job a few weeks ago using aftermarket rotors (Duralast Gold) and my gas mileage dropped by >5mpg.

The wheels definitely spin freely, no noise, no apparent rubbing at all. BUT after driving around the temperature of the brake drums gets up to ~170F while the rotors themselves are only around 80F (same as the front). So the parking brake shoes are definitely dragging somehow, and pretty much equally on both sides.

The cables seem free, the adjustment is backed off as far as it will go, all the misc springs & clips that hold the shoes in place seem fine. All I can think is that the aftermarket drums are slightly undersized, but I haven't had time to pull one off to measure yet.

Anyways, something else to consider if your mileage has dropped suddenly.

 

[Drobs]

This is a great thread. A lot of great information.

I have a 2020 Offroad Premium and am having what I'd call extreme poor mileage. I do have some modifications that I suspect are contributing, but they should not at the level that I'm seeing. I have a 2" leveling kit in the front and 285/70R17's KO2's. I also have a bug deflector. I do need to install a 1" body lift to stop my tires from rubbing on a sharp turn in reverse. This won't help, but do want to keep the look and like the performance of the tires. I have less than 1000 miles on it, it's still breaking in also, but still seems extreme.

My mileage is better in town/city than on the highway which is a bit confusing. I actually see the mileage in the city to be around 17MPG average and Highway drop to lower 14MPG's. Also if I drive in the 75 to 80 MPH area it drops to high 13's.

So far, I like the vehicle. It's my first, I traded a Tacoma for it. Not impressed with the power, but it does get me where I need to go.

Wondering if anyone else is seeing anything like this with the 2020.

Thanks.

In my experience heavy tires = poor mpg.
That and speed.

I got 13mpg with all the below mods (minus the sliders) pulling my boat home from Minnesota over the course of 900 miles.

I'm still get 18mpg with my sliders.

 

[TeaMan]

In my experience heavy tires = poor mpg.
That and speed.

I got 13mpg with all the below mods (minus the sliders) pulling my boat home from Minnesota over the course of 900 miles.

I'm still get 18mpg with my sliders.

Thanks, appreciated.
TeaMan

 

[TeaMan]

Ideas for effieiency

Anyone done any of these ideas for fuel economy?

1. Exhaust changes such as Cat Black to gain flow, or reduce resistance?

2. Intake air box modifications such as K&N air box?

3. Electric Fan?

4. Different gearing?

I don't know what the newer fans do, but I remember in my early days, the fan consumed a couple HP.

Just curious what others may have tried. I've seen a quite a few posts on what takes away from the mileage, but not a lot on what may add to it.

Thanks
TeaMan

 

[JayceeP]

Yeah.... mpg is not the best but.... knock on wood... over 7 years of ownership, aside from the regular scheduled maintenance/brakes/tires, the only thing I’ve spent money on is a new battery (2 months ago and was part of a maintenance service). The lack of dealership visits alone is worth the hit in fuel economy. I have not once visited the dealership for anything but an oil change/maintenance visit.