Highway MPG report

[WXman]

Ok cool I'll take your word for it. Just didn't make sense. A 2013 has 25 more horsepower than a 2004... BUT is has 4 less lb/ft of torque, and is simply bigger and heavier. To take less torque, and move a larger vehicle, and still get better mileage....that's pretty d*mn revolutionary.

But if it's really happening, you guys have some nice rides. For what the 4 runner is, it does pretty well.

 

[Viper45]

Correct me if I'm wrong, but if you hand calculate MPG wouldn't you have to fill the fuel to the same point, every filling, to even remotely have accurate numbers.

For instance, if you top off the tank at the beginning of a long trip, then at the next fill up stop when the auto kick off stops the nozzle, it will say you used less fuel than you really did; thus incorrectly reflecting a higher MPG, right?

 

[eddiebx]

Correct me if I'm wrong, but if you hand calculate MPG wouldn't you have to fill the fuel to the same point, every filling, to even remotely have accurate numbers.

For instance, if you top off the tank at the beginning of a long trip, then at the next fill up stop when the auto kick off stops the nozzle, it will say you used less fuel than you really did; thus incorrectly reflecting a higher MPG, right?

I think for the most part hand calculating is pretty accurate as long as you measure it across a larger sample size, like 3/4 of a tank or more...

I'm sure the auto stop function of the nozzle varies a bit from pump to pump, but usually it should be reasonably close. Let's just say it's within a +/- 0.2 gallon difference. If you factor that variation into say a 15 gallon fill up it would look something like this:

300mi / 15.0 gal = 20 MPG
300mi / 14.8 gal = 20.3 MPG
300mi / 15.2 gal = 19.7 MPG

So as you can see above, worst case scenario is you'd be off by about +/- 0.3 MPG from one fill up to the next, which is pretty minuscule in the grand scheme of things.


Just for fun, let's say you do this across the entire tank for maximum accuracy:

460mi / 23.0 gal = 20 MPG
460mi / 22.8 gal = 20.2 MPG
460mi / 23.2 gal = 19.8 MPG

and across a very small sample size to show the inaccuracy:

100mi / 5.0 gal = 20 MPG
100mi / 4.8 gal = 20.8 MPG
100mi / 5.2 gal = 19.2 MPG

Now you can probably see what I mean by the larger the sample size, the more accurate the calculations because the larger sample can absorb the variation much better with out affecting accuracy.

 

[2013Trail]

I haven't seen 22 mpg on the highway. I have seen 20-21 mpg on the highway. I am presently averaging 18-19+ mpg mostly city driving. I usually drive at 3-7 mph over the speed limit when on the highway depending on where I'm driving. Around town I don't have a heavy foot.

 

[Viper45]

I think for the most part hand calculating is pretty accurate as long as you measure it across a larger sample size, like 3/4 of a tank or more...

I'm sure the auto stop function of the nozzle varies a bit from pump to pump, but usually it should be reasonably close. Let's just say it's within a +/- 0.2 gallon difference. If you factor that variation into say a 15 gallon fill up it would look something like this:

300mi / 15.0 gal = 20 MPG
300mi / 14.8 gal = 20.3 MPG
300mi / 15.2 gal = 19.7 MPG

So as you can see above, worst case scenario is you'd be off by about +/- 0.3 MPG from one fill up to the next, which is pretty minuscule in the grand scheme of things.


Just for fun, let's say you do this across the entire tank for maximum accuracy:

460mi / 23.0 gal = 20 MPG
460mi / 22.8 gal = 20.2 MPG
460mi / 23.2 gal = 19.8 MPG

and across a very small sample size to show the inaccuracy:

100mi / 5.0 gal = 20 MPG
100mi / 4.8 gal = 20.8 MPG
100mi / 5.2 gal = 19.2 MPG

Now you can probably see what I mean by the larger the sample size, the more accurate the calculations because the larger sample can absorb the variation much better with out affecting accuracy.

Makes sense when you're comparing just the auto stop on the nozzles, but I was more or less referring a different situation. Before starting a long trip, you proceed to top off the tank, and the filler tube, to the point where you've added another 1.5 to 2 gallons of fuel after the auto stop from the nozzle first stopped. Here are some of my real world examples that (I think) should reflect both of our examples. Please reference My fuel usage in google doc spreadsheet. (Note that I reset my tripometer A and 4R MPG display every fill up.)

If you look at the first 5 fill ups in Apr 2013, you will notice the reading is damn close to the hand calcs. This was intentional, I would stop adding fuel when the auto stop on the nozzle kicked in, so that I would have a standard to measure from and so I could cross reference display readings vs hand to see how accurate it was. Once I was comfortable that I could rely on it, I added fuel past the auto stop so that I could increase my range. I feel this data displays the same characteristics you showed earlier in the post I quoted.

Now look at the last fill up on 08/19/2013. The 4R readings display said I got 19.9 MPG, but the hand calc is 17.4 MPG. Why? I would imagine it's because I sat there and topped off the entire tank, up to the point where I literally couldn't add any more fuel without spilling. Why did I do that you ask, simple I went into the mountains yesterday and don't have extra gas tanks yet to bring along.

314.9mi / 19.9 MPG = 15.8 gal (when I actually added 18.046 gal)
18.046 - 15.8 = 2.2 gal more!

So applied topped off tanks to your examples we get:
---------------------------------------------------------------------
Nozzle autostop: 300mi / 15.0 gal = 20 MPG
Tank top off: 300mi / 17.0 gal = 17.6 MPG (13% difference)

Nozzle autostop: 460mi / 23.0 gal = 20 MPG
Tank top off: 460mi / 25.0 gal = 18.4 (8% difference)

Nozzle autostop: 100mi / 5.0 gal = 20 MPG
Tank top off: 100mi / 7.0 gal = 14.3 (40% difference)
---------------------------------------------------------------------
I'm not positive, but I would imagine the people that are not getting displays to match hand calcs are not consistantly adding the same amount of fuel they used. Which using the data above is easy to see where mistakes can be made. (edit - also, please feel free to point out my errors or incorrect assumptions if any, I'm just trying to relay what I've noticed across my sample of data.)

That said, I do think the 4Runner display is correct. And I am amazed that I can net 19.9 MPG traveling through traffic/construction to CO Springs - then up US24/CO67 through Woodland park to Deckers; then 3-4 trips along the South Platte River and our campsite while tubing - then the return trip back home back home.

 

[eddiebx]

[MENTION=94592]Viper45[/MENTION] I think I am finally on the same page as you and get what you are saying. It seem's like we're both pretty much doing the same thing, except you're filling up to a more measurable point; which just goes to show that there are discrepancies between the computer calculated vs hand calculated figures.

I'm one to be a stickler with these kind of things so what I do is just take the computer calculated figure and the hand calculated figure and average the two and call it a day. Close enough, IMO

One thing though, I would suggest you not top off the gas like that anymore, and just stop after it auto stops or one ore two clicks more, max (there's some opening that drains gas into some emissions canister or something and screws it up big time). If you constantly over fill up to the point you can see the gas in the fill tube, you're eventually going to break something that costs big bucks to replace, I think. I can't seem to find the thread right now, but if I do, I'll post it here.

 

[Viper45]

One thing though, I would suggest you not top off the gas like that anymore, and just stop after it auto stops or one ore two clicks more, max (there's some opening that drains gas into some emissions canister or something and screws it up big time). If you constantly over fill up to the point you can see the gas in the fill tube, you're eventually going to break something that costs big bucks to replace, I think. I can't seem to find the thread right now, but if I do, I'll post it here.

Wow, never heard of that, I'll try searching too; thanks for the heads up. (edit - guess I need to find those fuel tanks that mount to the gobi, quicker than I thought )

 

[eddiebx]

Wow, never heard of that, I'll try searching too; thanks for the heads up. (edit - guess I need to find those fuel tanks that mount to the gobi, quicker than I thought )

Here ya go buddy:

http://www.toyota-4runner.org/4th-gen-t4rs/134981-full-gets-gas-pump.html

And while we're at it, I found this friendly remind from the EPA, lol: Don't Top Off Your Gas Tank! | Mid-Atlantic Air Protection

I know that link is for a 4th gen, but I think most modern cars all have this, so it should probably be applicable to us as well.

 

[Viper45]

Well I'm sure the reason I haven't seen any symptoms yet is because I only top off for long trips, which when I do, I use up 1-2 gallons in the first 30 minutes of the trip. (Ir?)Regardless, time to stop, thanks for the links.

 

[JayceeP]

Correct me if I'm wrong, but if you hand calculate MPG wouldn't you have to fill the fuel to the same point, every filling, to even remotely have accurate numbers.

For instance, if you top off the tank at the beginning of a long trip, then at the next fill up stop when the auto kick off stops the nozzle, it will say you used less fuel than you really did; thus incorrectly reflecting a higher MPG, right?

At the beginning of a long trip, why wouldn't you just stop fuelling when the auto-stop kicks in? Problem solved.

 

[Viper45]

Most of my "long trips" occurs on 2 lane roads in the middle of literally nowhere WY, MT, and ND (and I end up basically near the :canada: border). Additionally, 1/2 of the year these same trips occur during the winter time in variable conditions, and I would like to leave 1/4 or more in my fuel tank should I have to pull over and wait it out the storm in negative "oh ****ing shit cold weather". (edit - Also, most of the small towns I pass through are sketch, and I have no idea where they get their fuel.)

 

[hawkman]

Maybe for a new thread, but,.... when filling up.. do you fill at the fullest/ fastest rate the pump pumps at?
or...
do you fill it s.. l.. o.. w.. l.. y....

a friend said that going slower doesnt create as many air bubbles, or foaming in the gas, allowing more fuel into the tank..

thoughts?

i always use the pump's slowest lock setting... havent done any real research personally.
but i do not like the hard SLAM shut off.. and i always gently squeeze the the trigger to "release pressure" from the shut off to top off.

psychological? pressure release?

 

[Jayhawk5G]

Sorry I have been up in Michigan the past couple days...

She was doing 70mph up to 75mph at times, and she led the pack.

 

[SR5inSLC]

To add one more data point:
Two weeks ago we made an 1100+ mile road trip in our 2012 SR5, from SLC to a dude ranch near Chama, NM, and back.

Calculated MPG (total miles/total gas) for the trip was 23.9 MPG.

I'd guess there was ~200 mi of interstate at 75+ MPH, <200 mi driven at < 50 mph (~50 mi gravel in 4WD), and the majority was other highway at speeds of 55-70 MPH.

My SR5 is absolutely stock, purchased new in Dec 2012. With ~8000 total miles after 8+ months, the trip computer shows an average fuel economy of 18.5 MPG.

 

[Jayhawk5G]

To add one more data point:
Two weeks ago we made an 1100+ mile road trip in our 2012 SR5, from SLC to a dude ranch near Chama, NM, and back.

Calculated MPG (total miles/total gas) for the trip was 23.9 MPG.

I'd guess there was ~200 mi of interstate at 75+ MPH, <200 mi driven at < 50 mph (~50 mi gravel in 4WD), and the majority was other highway at speeds of 55-70 MPH.

My SR5 is absolutely stock, purchased new in Dec 2012. With ~8000 total miles after 8+ months, the trip computer shows an average fuel economy of 18.5 MPG.

Interesting after these trips back and forth to get moved up here, we are at 8,800 miles so roughly the same overall miles and mpg. Before we reset it to get pure highway mileage my long term average was between 17.4-18.1.

 

[dwc]

SO this past weekend my wife and I loaded a couple 24 ft Budget Moving trucks, and her father and I drove those for the big move to Chicago (West Suburbs) and my wife drove the 4Runner with the rear seats folded down and all our fragile stuff loaded in...

I know that highway MPG was rated less for 2013, but am happy to report that with the MPG average reset, my wife averaged 23.5 mpg over approx. 533 miles during the trip. She reported being at 24 for about half the trip, but advised that as the terrain added more and more hills the MPG dropped slightly.

This seems to be in keeping with Toyota from my experience. The newer models I have driven seem to be a bit conservative on MPG ratings. Thought I would share, and though terrain plays a huge factor it is possible to get pretty damn good mileage from these trucks.

You're doing much better than me. On my trip out and back to the FJ Summit I averaged around 19 mpg. After the first 2500 miles I turned off the green Eco light and now just fill it up when the idiot light comes on.

 

[poolzer]

just hit 60k in mine and still get typically 20.3mpg doing 95% highway driving.

 

[diverscale]

just hit 60k in mine and still get typically 20.3mpg doing 95% highway driving.

At what speed is this?

 

[JayceeP]

At what speed is this?

I achieved that exact fuel economy driving from Saint John, NB to DC. This includes traffic thru Boston, hotel stop, gas stops, small amount of traffic at the GW Bridge, and terrible traffic into DC. I did 120-130kph whenever I could.

 

[Jessrin]

I'm Avg at 22 mpg with my 2010 SR5 v6 4x4. Please note I only drive 55 mph and thats the speed limit on US HWY 2. 13 miles to work and back. I'm very easy on my pedal too... Yes.. Driving 55 is slow. you do get some people very mad at you.. oh well.. Plus its a few more minutes to bond with my runner!. :yo: