lmc

CAR: TL Advanced AWD, 2013 Automatic

There was an earlier discussion about MPG actual versus trip computer numbers, and so I've done a detailed set of record keeping to report back.

Over the last couple of months, we've take some family trips around Oregon/Washington; and then just last week completed a round trip vacation from Portland, OR to LA and back.

Below is the table of stats, but here is a couple of conclusions: Car Trip Computer seems to be "under reporting" actual MPG about 5%. This conclusion is based on over 3,000 miles and 9 fillups.

Also, "pure" highway driving MPG will average over 28 MPG. This included mulitple climbs up to 4,000 ft mountain passes, mix of hot AC use and fresh air, two to three passengers and mix of speed limits of 65 and 75 MPH.

Also, in 60-65 MPH highway driving with BIG hills, no AC, 2 people, I get 29 MPG.

(I have the spreadsheet if anyone cares. Doing a table in the forum is messy.)

Attached is a Excel Text file and an image of the Excel data.


Gallons—Odometer--Calculated---Computer---driving--------Notes
------------------------MPG---------MPG--------Type
07.68-----2,557- ---First-official-tracking-entry---
15.26-----2,967-------26.9-----------25.6--------Mixed
10.26-----3,275-------30.0-----------28.3--------Hi-way---75-degrees-two-people,-some-freeway-traffic
13.10-----3,619-------26.3-----------25.1--------Hi-way---No-AC
15.60-----4,042-------27.1-----------26.4--------Hi-way---Some-mountains,-some-AC
13.86-----4,406-------26.3-----------25.7--------Hi-way---Some-Mountains,-AC
11.52-----4,646-------20.8-----------20.0--------Mixed ---LA-driving,-AC,-Traffic,-90-degrees
17.00----4,975--------19.4----------22.8---------City------LA-driving,-AC,-Traffic,-90-degrees,-2-hr-Traffic-Jam
12.25-----5,390-------33.9----------26.1--------Hi-way ---AC,-80-degrees
09.90----5,668--------28.1----------27.3--------Hi-way ---AC,-80-degrees

-------------Average--26.5----------25.3-

jason60050

Yea the city mpg is pretty horrific...then again the hwy mileage is pretty good.

JM2010 SH-AWD

Thanks. This is about what I get with my 6MT.

Although I have to say, I still believe it's really difficult to get an accurate reading with the "calculate by hand" method. Even if you use the same pump every time you fill up, depending on temperatures, how the pump is set up, how quickly it's filling the tank, etc., it's virtually impossible to ensure you're always filling it up to the same exact point every time. That is why I believe the on-board computer could be more accurate.

Either way, this is excellent mileage for a large, AWD, 305 hp car, no?

jason60050

I think the hwy mileage around 28-30 is fantastic. Having said that I think 19 in the city is pretty bad in my opinion. I drive 90% city and my computer has never gone over 20.3.

jim_c

That's true but the OP calculated the average over 3,000 miles which should make for a pretty accurate result.

That's quite impressive hwy mileage but it would be even better in Canada. Our "gallon" is 20% bigger! lol

Thanks for posting and doing the math!

amill

I've noticed in my last few acura/honda products that their fuel consumption computer was the closest to "real world calculation" out of any cars I've ever owned. They do usually read a little low, but due to many factors they may be right. Either way, I average nowhere near that kind of mpg. I think the best I've ever gotten was 22.X mpg overall on a tank. I do drive about 60/40 city/highway.

lmc

Note that my daily drive car is an electric Nissan Leaf. The TL is our weekend, long drive car. So no real city driving or short hops.

Cygnus_X1

My 2013 TL gets about 14 mpg driving around town? I admit I mostly make short trips but even my 2007 Avalon got 20 mpg in the same environment? I think my next car will probably be a hybrid....maybe a TLX hybrid if they make one.

Mr Marco

emanon256

I was getting 17-18mpg in town until I did the transmission software update, now I get around 14mpg in town. I figured the 2013 would be better with then 6 speed. My 3.2 1G TL got about 22Mpg and my S2000 got about 25Mpg.

I too am hoping for a TLX hybrid.

mightl

Thanks for sharing.
My computer mpg matched to my manual calculation in the first few thousand miles, hence I trusted it ever since. I'm surprised that some of yours presented huge gap in between. I guess it's about time for me to do some cross check at 20K.

jim_c

I've been tracking my mileage and it seems that the trip computer result is very close to what I calculate "manually" with miles travelled over actual gas at fill-up. Computer seems to be very slightly lower than what I calculate. My question is :
Does anyone here understand how the car "knows" how much gas is being used? The trip computer calculates average consumption and also instantaneous consumption. How does it know the rate of gasoline usage? Does the ecu do an ongoing calculation of fuel flow through the injector system and integrate over time? It's pretty sophisticated.
I know there is a mass air flow sensor which feeds the ecu continually. Is there also a "fuel mass sensor"? It seems there must be, right? The computer must keep track of fuel usage over time during the course of a tankful of gas and save that data until it resets. (?)

jim_c

And similarly, how does the computer know to set the "A" mileage odometer back to zero when you get gas? (If it's programmed to do so) Perhaps the gas guage in the tank sends a message to the computer to say that gas has been added, so go back to zero. (?) What if you just open and close the gas cap but do not add any gas. Would the computer be fooled into resetting? (I don't think so....) Just curious as to how the car does these tricks!

potmilkz

only resets if you add gas, not sure how much you need to add to make it reset but ive added half a tank and it reset on me..
ive always used this method..

if you arrive into a gas station with your gas light on, just look at mileage A for example 380, then pump your gas, see how much gallons you just pumped.. lets say 17 gallons, divide 17 gallons into 380 miles and you get your rough mpg. which should be about 22.35 mpg

potmilkz

i cant answer all your questions, but i can tell you what i set for my A and B sections of my display

A is for my tank of gas that i use till i fill up my next tank. it resets every time i fill up..

B is for my overall tanks of gas i use before i get my next oil change. Right now my B side has about 6000 miles which is rated at 23.4mpg. My B side shows my overall MPG over the course of many tanks of gas used.

emanon256

I do the exact same as Pot with my A and B. Also, I have topped it off before been down 3 or 4 gallons, but about to go on a long trip and filled it before I left, and my A still resets.

I listen to Car Talk religiously and they were recently saying that modern cars actually do have a fuel flow sensor that constantly monitors the volume of fuel as its being used. This is how they calculate the instant and average MPG, as well as miles until empty.

One thing I don't like about the TL is how the miles until empty jumps all over the place. Other cars I have driven use a much longer time frame to calculate it. When I am driving uphill, it can drop my 40 to 60 miles until empty and then when I am going back down hill, it jumps up my 50 to 100 miles until empty. I finally stopped using it and always keep the instant MPG up to try and use less fuel.

lmc

I believe the "auto reset" with fill up is an option that can be turned on or off. I've got mine OFF so that I can capture all the data after pulling away from the pump to manually record the data.

DefMunkie

Yes it can.

Trip B is my overall calculator throughout car ownership and Trip A is on Auto reset to calculate per tank.

emanon256

I pull it all while I am filling up and let it reset on its own. I'm a rebel, I ignore the signs that say do not get back into your car while filling up.

potmilkz

jim_c

Thanks for the replies. Yeah, I have mine set so A is the current tankful and B is the total since I got the car. I have the A set so that it rests at fillup. It takes a couple seconds after you put it in drive and start to pull away from the pumps, then it goes back to A=0. I was curious as to how the car can calculate fuel usage "on the fly". I guess as Emanon said, there must be a fuel flow sensor and the data is captured and saved by the trip computer.

The range until empty is just an estimate and it fluctuates because (I think) the computer figures what usage you are averaging now and how much fuel is left. Obviously if you drove very slowly your range might be 50 miles (e.g.) but if you drove faster the range would be reduced. If you coasted all the way the range would increase.

potmilkz

yea i think the "range" calculates realtime data as your driving.. im sure you notice when your light is on, it will say 50 range, then as you cruise or gas it you will see the range move up or down.

Six Shifter

in my experience, the computer calculation was always around .5 miles low when compared to the manual calculation. Also ... mine reset each/every time based on (I used to think) the simple removal of the gas cap ... although I never bothered to test it. However, I pulled the car up on racing ramps to install my Nexson grill, and when I backed off the ramps, the fuel gauge had reset, telling me the float play some part in the process.

sluzynsk

I've had it reset when the level was low from coming off a steep hill, so I believe that the float resets it as well.

Mr Marco

I see cheif of delete has been trolling my posts again...

TLMDXRDX

I will be getting my new RDX in another week or so and am curious if anyone that does mainly all city driving is getting near 21 MPG on the AWD model? My current 2010 MDX was rated 16 city and 20 highway and I am averaging just over 15 MPG for 95% city driving. I am hoping the new RDX will get me close to 20/21 for the same 95% city driving...but that might require I get rid of my lead foot.

horseshoez

iTrader: (2)

Hmmm, you might want to post in the appropriate area; you've just revived a 5-year old thread for an Acura TL.

losiglow

iTrader: (1)

I think it's good to resurrect a thread if it's a pertinent comment. But I'm not sure yours has much to do with the original topic. I'd probably post in the general 3G RDX forum with your question. Not many 3G RDX'ers are going to be checking out the 4G TL forums.

dopeboy1

Im sure he knows the difference between a new RDX and a 4G TL lol. This resurrection wreaks of being an infinite scroll victim.

But while were here I've started tracking my actual MPG and im at 17.5. All city with very short hops on the highway. Some vtec and reving.... not bad.

losiglow

iTrader: (1)

That's not bad if you're pushing it a bit and in the city. I rarely get less than 25, even in the city. But I drive like a grandma 90% of the time and my "city" driving tends to be on less congested roads at lower speeds with traffic lights that are pretty well timed

dopeboy1

I think I read that the sh-awd is rated at 18 mpg city. So im pretty happy with 17.5 considering how im driving. But dang 25mpg city is impressive. I know some of that is being FWD but that's still really good.

TLMDXRDX

Oh I am sorry. I thought I selected the 3G RDX forum. I will go back and try that one instead.

Pearl77

After 1100 miles in my new Advance, I am getting about 24mpg (+or- about .5 mpg) on 93 Octane Top Tier gas, mostly in Comfort mode. This is mixed suburban/highway driving. I have made an effort not to "waste gas" by timing lights and otherwise driving carefully and only occasionally using the power. I am sure that I would get 2-3mpg less if I got on it more. Nice car that I like to drive, but it will not win any mpg contests against the best in this class.

horseshoez

iTrader: (2)

Interesting, I'm kind of surprised the newer cars get such low mileage; the absolute worst tank my 2006 TL has gotten is 27 mpg, and that was with a majority of bumper to bumper urban traffic.

losiglow

iTrader: (1)

I frequently got >30MPG with my 3G 6MT. I've never gotten better than 27 in the 4G. But it's heavier and an automatic so that sort of explains it.

dv-

I'll get 31+ on long highway trips (4G 6AT FWD), but city driving kills it. :-(

kickarsmann

2009 TL (5AT) here averaging around 22-25mpg between traffic and highway. I get 27-28mpg highway.

mdb007

My 12 I just bought was showing 26mpg going to Michigan from ohio while cruising into headwind at 80mph with cruise on. On way back was cruising at 74 and it went back to 28mpg and when I filled up that was what i got 28mpg for trip! So much better than my inefficient 07 maxima which got 24-25mpg on hwy and 22-23 around town. and with my 235lb weight pushes car to almost 4000lbs, that pretty good in my book.