Real World MPG with 5th Gen?
- Thread starter AZDropTop
- Start date
Panzerpatty
New member
Random increase in mpg?
2 weeks I reset my digital mpg display and I went from 15.2mpg to 17.5mpg. My mpg has been consistently 15ish for about a year now(after mods). I went to the gas station 2 times and on both fills I was at ~17 after doing the math!
27k miles on a 2015
Same driving habits
Same commute
Same gas station
Same tire pressure(33psi)
The only thing that I have done recently is install a bluetooth OBDII port and installed torque/carista, but I didn't fiddle with anything.
I'm not complaining, but it's driving me crazy. Has this happened to anyone else?
2 weeks I reset my digital mpg display and I went from 15.2mpg to 17.5mpg. My mpg has been consistently 15ish for about a year now(after mods). I went to the gas station 2 times and on both fills I was at ~17 after doing the math!
27k miles on a 2015
Same driving habits
Same commute
Same gas station
Same tire pressure(33psi)
The only thing that I have done recently is install a bluetooth OBDII port and installed torque/carista, but I didn't fiddle with anything.
I'm not complaining, but it's driving me crazy. Has this happened to anyone else?
1engineer
Moderator
1. Don't trust you digital display. Do the calculations manually.
2. We did not need another mpg thread so I merged it with the 61 page thread on the same subject.
-mod-
Panzerpatty
New member
Thanks bud. As you can see in my post, I did do the calculations manually. 2 fills same result.
1engineer
Moderator
Maybe this will help - I wrote it a few years ago... http://www.toyota-4runner.org/5th-gen-t4rs/157694-how-your-miles-empty-range-indicator-operates.html
Panzerpatty
New member
Forget the digital display part of it. That's just what tipped me off. I've calculated my mpg 1980's style for the last 2 years and in the last two fill ups I've gained 2mpg, that's the takeaway.
FrontRange4Runner
New member
2 fills is not a meaningful sample. Environmental changes could easily account for this.
Also, I get about 18 mpg combined running LR E tires. Has been this way for about 65K miles.
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Gecko
New member
Disclaimer: I've read all of the articles about "American's waste __ dollars per year buying premium gas when their vehicles don't need it," and I have always just run regular in vehicles that require regular. Never saw a need to deviate from what works.
My 4R has about 5,300 miles on it now and I've always run Shell regular 87 octane.
On stock wheels and tires (20"s, Geolanders), I was averaging 16 MPG.
Once I went to the 17" wheels and KO2s, I went down to 14.5 MPG.
Two weekends ago, I had some spare cash in my wallet and decided to fill up with 91 just for the hell of it. Didn't really notice any difference in power, but I realized today that I've been on the same tank for about a week and a half, and I usually buzz through a tank a week. I looked at the info screen and also hand calculated and I got about 16.3 MPG using 91 octane. I'm a little surprised and may continue to run 91 for another tank or two to see if this continues, and then switch back to 87 to see if it drops.
Just my .02
My 4R has about 5,300 miles on it now and I've always run Shell regular 87 octane.
On stock wheels and tires (20"s, Geolanders), I was averaging 16 MPG.
Once I went to the 17" wheels and KO2s, I went down to 14.5 MPG.
Two weekends ago, I had some spare cash in my wallet and decided to fill up with 91 just for the hell of it. Didn't really notice any difference in power, but I realized today that I've been on the same tank for about a week and a half, and I usually buzz through a tank a week. I looked at the info screen and also hand calculated and I got about 16.3 MPG using 91 octane. I'm a little surprised and may continue to run 91 for another tank or two to see if this continues, and then switch back to 87 to see if it drops.
Just my .02
neatoneto
New member
Currently sitting at 21.5 after some city driving but I hope to average 22 by the end of the tank. This should give me a range of ~380miles once it hits 0miles left. Truck is all stock (17" Firestone Duellers).
It could be because I'm used to driving stick shift so I know how to feel out the engine and transmission!
007Tacoma
New member
Interestingly enough - as long as I am not spending excessive amounts of time idling (no more that 10 minutes per tank), my fuel economy on my cluster is not usually off by more than 1.2 MPG. The less I idle, the more accurate it is.
(granted, I am still in stock size tires in my 2015 TEP)
zcruiser
Senior Member
There is more energy in 91 octane... Have to determine based on $/gal whether $/mile works out to be same/better/worse. You could also get the same type of benefit if you run non-ethanol. More energy/gal...
If you get 15% better mileage (increase by 2 mpg) but you spend 20% more per gallon, then you're not gaining anything.
ETA: Octane energy benefits apparently are incorrect, my apologies.
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TEujunga
New member
Wow, that's fascinating. Every single reputable source I have ever encountered insists that the all pump gasoline has basically the same "energy content" and that the only significant difference between different grades of gas is the resistance to detonation. I guess they all must be wrong, huh? I'd be interested to see some citations to back up your information.
Back on topic with this interesting tidbit:
1,000-mile interstate trip with stock suspension and Bridgestones: 20.4 MPG
Exact same 1,000-mile trip under similar conditions and speeds with the only change being a 2.5"/1.5" suspension lift and tires: 18.5 MPG
zcruiser
Senior Member
Willing to admit I'm misinformed, just reflecting my experience. I think we can agree that non-ethanol has more energy, eh?
Did your tire size change? Did you happen to verify speedo accuracy?
RysiuM
New member
Absolutely not true. The extra energy is from the combustion conditions, meaning engines designed for high octane fuel (high compression) can get more "bang for the buck" compressing the fuel/air mix to higher pressure before igniting it.
4Runner engine does not get higher compression ratio by using higher octane fuel. It will burn a high octane fuel exactly the same way as regular 87 (octane fuel this engine was designed for). If you put lower octane fuel than 87 than it is different story. The engine will try to compensate for "explosive burn" by delay spark and trying to prevent knocking (the pressure from burning fuel occurred before TDC). This will cause a lower power but will save the engine from knocking.
So the bottom line is - higher octane fuel than the engine is designed for is just pure waste of money. Using a it lower octane fuel is less power for the amount of fuel burned. Using to low octane fuel can harm the engine if the computer can't compensate.
TEujunga
New member
Agreed on the lower energy content for gas with ethanol. I'd be interested to see some controlled test results for MPG using straight gasoline vs. 10% ethanol. That could conceivably be a meaningful enough difference to justify paying a bit more for straight gas. But how much more?
As for the questions on my tire size and correction for speedo accuracy: yes and yes.
Turns out my speedo/odo accuracy didn't change much with the switch to 275s -- in my case, the difference in real-world running diameter is evidently not very significant. Even theoretically, the difference is pretty small: 1.7% or thereabouts.
My 20.4/18.5 results are based on actual miles traveled and actual fuel consumed, not on the in-car readouts, although they were pretty close.
zcruiser
Senior Member
TOPTEAM
New member
Those were my exact thoughts because I'm averaging about 15mpg in the city as well... I don't see our trucks doing 18mpg in the city. People are most likely not resetting when comparing the city vs highway.
Please report back when you can if you've continued the 91. I don't see how others are getting close to 20, I've been averaging 15.8 for the first 5300 miles. I do pull a small tool trailer during the week but it's not heavy. Monday I put trd wheels and ko2's on mine, still hanging at 15.7 but expect it to drop. Fwiw I have a limited also, maybe it will get better after a few more thousand miles?
