KilroyR1

I've always thought the accuracy of the MID miles per gallon estimate was a little off, to make owners feel better about their gas mileage.

Anyway, for my last tank of gas, I reset the mileage statistics and went 333.8 miles and it took 14.454 gallons to fill it for an actual MPG of 23.09 MPG. Miles to empty said 7 (I know this is way off).

The MID indicated 24.

So, if the MID rounds 23.5 to 24, it's only off about 0.4 MPG: not bad.

I'm taking a highway trip to NYC this weekend, I'll see how that goes.

Has anyone tried this on their own? If so, share.

mbwmn

did a trip to VT (from NJ) and another to ME. both times the mpg was accurate to w/in .6mpg....

DMZ

Yeah, it rounds off and is pretty accurate. Still, I fault Acura for not making it an instantaneous MPG display as you drive as it would help everyone adjust their driving habits for maximum mileage, something found in the form of a small analog guage in every Beamer from the bottom end 325 on up. If I want average MPG for the tank, I can just as easily use a calculator at fill up.....DUHHH.

What pisses me off is that the same Nav system available in the Accord not only incorporates the trip computer on the Nav display where it belongs with much more detailed trip info, but also HAS a graphically oriented instantaneous MPG display as well! We TL buyers pay $thousands more, and are therefore entitled to the same or better functionality, NOT LESS !!!
.
.
.
...
ACURA on this one!

bonanza829t

Yeah, I have to agree on the lack of an instantaneous MPG display. I have that feature on our 1999 Passat and find it very useful for obtaining the best mileage.

Another thing that the Passat has over the TL is sequencing throught the MID via a rocker switch on the washer control. Your hand never need to leave the wheel to change the MID display.

Oh, well. Can't have everything I guess. The TL is still a great care, but I agree that the TL should not be missing features found on the Accord.

PhilB

I have recorded the MID info as well as actual miles travelled, fuel added and fuel price for every fill-up since I bought my TL almost 1 year ago. Here is the MID MPG and actual MPG data through 8/16/05:

MID ------- Actual
------------------------------
19 -------- 19.66371183
19 -------- 19.07848497
19 -------- 18.90777217
19 -------- 17.19355066
18 -------- 17.50050638
18 -------- 17.49926751
18 -------- 18.23078058
18 -------- 18.38577481
20 -------- 20.08232236
18 -------- 18.37849191
17 -------- 17.4056673
18 -------- 18.15199563
19 -------- 19.58001863
18 -------- 18.08019278
20 -------- 20.08324662
20 -------- 20.12314582
17 -------- 17.53146853
16 -------- 16.6572717
17 -------- 17.26500411
18 -------- 18.19446376
20 -------- 20.32818109

-phil

elenaran

wow, nothing over 20... someone has a lead foot!

jdb8805

Based on the superb accuracy of the rest of the samples, I would question the gas pump accuracy or calculations on this one. It's odd that it would be that far off on just one.

PhilB

It's all city driving. The only time I get on the highway is for 5 miles of stop and go traffic in the morning when I take my kids to school. The rest of the time I'm on roads with stop lights every 1/2 mile.

-phil

PhilB

I probably copied the data from the MID wrong. That was on Jan. 22 so I can't recall what happened there.

-phil

PhilB

In case anyone's interested, here's all the data I've collected. Notice the increase in gas prices. This data doesn't include the post-Katrina gouging when gas went over $3/gallon.

-phil


Date ___________ Range ____ Avg Fuel Economy __ Avg Speed _____ Distance _________ Fuel Added _________ Fuel Price
_____ _________ (miles) _____ (miles/gallon) ____ (miles/hour) _____ (miles) __________ (gallons) __________ ($/gallon)

12/12/2004 _______ 5 ___________ 19 ___________ 25 ___________ 279.5 ___________ 14.214 ___________ 1.889
12/29/2004 _______ 31 ___________ 19 ___________ 27 ___________ 244.3 ___________ 12.805 ___________ 1.869
1/10/2005 ________ 7 ___________ 19 ___________ 27 ___________ 265.9 ___________ 14.063 ___________ 1.839
1/22/2005 ________ 2 ___________ 19 ___________ 27 ___________ 244.2 ___________ 14.203 ___________ 1.939
1/31/2005 ________ 0 ___________ 18 ___________ 27 ___________ 259.2 ___________ 14.811 ___________ 1.969
2/10/2005 ________ 15 ___________ 18 ___________ 26 ___________ 238.9 ___________ 13.652 ___________ 1.919
2/20/2005 ________ 14 ___________ 18 ___________ 27 ___________ 247.1 ___________ 13.554 ___________ 1.949
2/28/2005 ________ 1 ___________ 18 ___________ 27 ___________ 264.7 ___________ 14.397 ___________ 1.949
3/9/2005 _________ 23 ___________ 20 ___________ 31 ___________ 278.1 ___________ 13.848 ___________ 2.049
3/20/2005 ________ 10 ___________ 18 ___________ 26 ___________ 262.5 ___________ 14.283 ___________ 2.129
4/3/2005 _________ 15 ___________ 17 ___________ 22 ___________ 237.1 ___________ 13.622 ___________ 2.319
4/16/2005 ________ 6 ___________ 18 ___________ 26 ___________ 265.6 ___________ 14.632 ___________ 2.289
4/25/2005 ________ 15 ___________ 19 ___________ 27 ___________ 273.2 ___________ 13.953 ___________ 2.289
5/7/2005 _________ 0 ___________ 18 ___________ 25 ___________ 270.1 ___________ 14.939 ___________ 2.239
5/16/2005 ________ 30 ___________ 20 ___________ 30 ___________ 270.2 ___________ 13.454 ___________ 2.239
5/24/2005 ________ 11 ___________ 20 ___________ 31 ___________ 287.6 ___________ 14.292 ___________ 2.199
6/10/2005 ________ 4 ___________ 17 ___________ 25 ___________ 250.7 ___________ 14.300 ___________ 2.219
6/21/2005 ________ 7 ___________ 16 ___________ 25 ___________ 236.4 ___________ 14.192 ___________ 2.269
7/18/2005 ________ 0 ___________ 17 ___________ 26 ___________ 252.0 ___________ 14.596 ___________ 2.399
7/30/2005 ________ 5 ___________ 18 ___________ 27 ___________ 261.6 ___________ 14.378 ___________ 2.399
8/16/2005 ________ 15 ___________ 20 ___________ 31 ___________ 277.5 ___________ 13.651 ___________ 2.769

KilroyR1

Wow, calculated out to 8 decimal places, that's precise! I'm impressed that the MID is that accurate.

Ron A

The MID column doesn't show any decimal places, only whole amounts of two digits. The actual column, achieved using a calculator unless we have a mathematical genius here, shows the result to 8 decimal places.

But the MID is consistently accurate, as long as you reset it each time you fill the tank. Failure to reset could result in large variances between MID and actual MPG.

Some people wrote in and said they never reset the MID since they bought the car and the average MPG shown by the MID is way off when they compute each fillup individually.

scrb09

I dont think that instantaneous MPG display helps AT ALL...I had it on my IS and I thought it was a waste of space...that thing used to go from 60 MPG while cruising to $10 MPG when you start from a red light...totally ridiculous... and just like the BMW it was a small analog meter...I mean everyone knows the basic fundamentals that if you gun the car you wont get good mileage compared to when you cruise you get good mileage...Its not like you are going to keep looking @ the meter (which swear to god changes every second from one end to the other) when you drive and change your style...

I think what our MID display is very useful.

Even the TSX has the same as the accord and when I asked I was told that they do not have a MID thats why they have it displayed on the NAVI screen...I dont see why would you want it at 2 places...

I agree that it is graphically represented differently....but it is still the same info.

SouthernBoy

I've seen it both ways. Last May, we took my wife's new '05 TL automatic on vacation. On the first leg of the trip the MID indicated 31 MPG. Actual was 31.25.

Bplayer

The best situation is having two displays just like the trip meter A and B. One could be used for this tank of gas, and the other for this trip.

KilroyR1

Re-reading my post, it does appear that my two separate thoughts are connected. I really meant PhilB keeps accurate calculations of his MPG and separatly, that the MID is very accurate.

Don

Brettg

What the VW has that is nice is a trip mpg.
It resets once the car is off for about an hour or two, so you get a display
of mpg for every longer trip, without having to cycle through menu's on
the dash button.
You could leave the display on the trip average mpg AND still have the outside
temp display, without having to do anything with dash buttons.

It is handy to have an instant mpg display, not that you would have it up much,
but its handy to look at sometimes when you are running on the hiway, you
can see what the actual MPG is, and see the effect of things like tire pressure,
gas type, temps, ac on or off, and speeds.
With the TL display, you would have to reset the thing all the time
to get something similar.
Acura should have a long term display, a trip display, and the instant display,
and one (at least) should be displayed all the time along with the outside temp.
You should not have to work through door lock settings and so on, using a hard
to find button on the dash to get to the info.

They have tons of space on the climate control/radio display to give you
a display that could be used, along with the station number, song title,
artist, etc, why you can only have ONE thing at a time is just stupid,
at least they should give the station number and something else.

I dont know who thought this stuff up but they need to find another line of work.

Brett

DMZ

Exactly !! Almost like the trip computer/MPG indicators on a Nav equipped Accord.

Whomever decided to give the TL the stripped down version should be fired!!!!

KilroyR1

Well, I did an all highway MPG check. I went 478 miles and averaged 68 miles per hour from Baltimore to NYC and back.

The MID indicated an average of 32 MPG and my calculation of miles / gallons was 33.09 MPG.

The actual fill up was done at 379 miles and the car took 11.454 gallons (the MID showed the same average MPG and speed at that time).

JetJock

IMHO...when you fill your tank, it's impossible to fill it exactly each time. Every pump clicks off at different fill levels and you can always coax an extra amount of gas into the tank so unless you fill it to the absolute maximum each time, your results are going to vary as much as the MID does. You'd have to fill the tank at least several times to get a decent "average" MPG figure. I've found my MID to be at least as accurate as my calculated MPG figures for each fillup.

SouthernBoy

You're right except for one exception. If you do the start and finish fillups at the same pump.

reisb

I hope mine is due to different pumps because on my 07 TL, I've done calculations on my last 2 or 3 fillups.

Todays - MID showed 27 mpg
373.7 miles and it took 14.89 to fill to first click
That is 25.1 actual mpg.
My last fillup was of 1-2 mpg also and I decided to fill to first click so I could compare. Unfortunately, it was 2 different stations.

But I think 2 mpg off is pretty bad.

italian_spak

i find this mpg pretty weird but i have thoughts that the cpu for the mpg calculator is wrong and is glitching

My driving is in overall always the same as city/hw driving, when i fill up i always reset my mileage and check the perspective of how many km's i will make with this full tank. Sometimes the mpg resumes 520km till empty and i will reach that mileage or may be off by 10-15kms and sometimes it will tell me around 450km till empty(70km difference) but ill have a hard time making it to 430km.

So what if the cpu is screwed up one day and i fill up and it tells me that i will do 200km till empty does it mean that the cpu will make me run super rich on fuel just to add up to 200km and not more???


what do you guys think about this?

KeithL

On my 04 and 06 TL I found the MID MPG to be very accurate, on my 07 I find it to be running about 1 MPG over so I have been averaging 22 and the mid usually shows 23.

Eoanou

The Acura 2003 MDX logged trip MPG for previous trips, up to as many as 10 previous trips, if you had the NAVI. I think that was a very neat feature, but oddly enough the 2004 RLs the generation before the one out now, they didn't even calculate MPG regardless of whether or not you have a NAVI, I always was curious why they had it on the MDX and not the RL of the same model year.

rwpow

I have the same concern as REISB.
For my '07 TL bought Jan 2, 2007:

Today's - MID showed 29 mpg
399 miles and it took 15.04 gal to the first click
That is 26.53 actual mpg.

Some (not very inspired) comments/explanations:
1. It's not likely that a late reset of the MID from the previous fill-up corrupted the MID mileage since the prior MPG value was much lower than 29 MPG.
2. If AVG MPG is computed by the Trip Computer the same way I do (total miles/total gal's) then MID 29 versus 26.53 actual is symptons of an accuracy problem. It's simply not Acura-te enough.
3. I guess it could depend on how AVG MPG is computed, if not as in 2. above. With the ignition on and the engine off, MID TIME continues to increase with no change in AVG MPH. With the engine running but parked, TIME will increase and AVG MPH decreases. I guess where I am going with this is that if for some reason Acura derives the MILES part of the MPG calculation by multiplying AVG MPH by TIME, then sitting with the engine off and the ignition on (as in a HF telecon) could distort the computed MPG by overstating MILES.

Might be a lame idea, but an 8% error on MID AVG MPG is also lame.

italian_spak

or maybe i was thinking that it might be a lack of octane concentration in the gas that can be srewing us over, i mean who does octance tests besides the gas company and who can prove otherwise???

rwpow

Respectfully don't see how octane enters into this - it's all about miles and gallons. At the end of the day, MID AVG MPG should match total miles divided by total gallons for the period in question.

italian_spak

well look ive done the test with all 3 sorts of gas from reg to super and the mpg was right it was displaying 330km a full with regular full tank of gas with super it had got up till 400km a full and to nearly 500km a full , the driving as always been the same but its since i have the car i fuel only with super like everyone does but the mpg plays tricks on me, knocking me off 60 to 70 km off my full tank,but it doesnt happen everytime so thats why not im thinking its the mpg system that is faulty

subhradyuti

In TSX, the MPG is shown in one place of decimal (like 20.2), and also there is one instantaneous MPG meter in the MID. Really surprised to know TL doesn't have this feature!

In TL, can you set the MID to automatically reset trip meter A (and hence MPG calculation) after each fueling?

reisb

Are you saying that is how they come up with the number they use for MILES instead of actual driven miles?

If so, you're right. That would overstate miles overall.
Right now I have:
34 MPH
289 Miles
9:17 Driving

9.283 * 34 = 315.6 miles driven instead of actual 289. That would overstate my MPG.

Wow!!! What a weak method of calculation. I'm sure that's on purpose to make it look better for us.

Best way to test is try to drive a full tank without ever having ignition on, but engine off.

Engine running with car parked would just lower our MPG, so that's OK. Just curious if it will still be high if I never sit with car off and radio on?

rwpow

I don't have any special knowledge regarding Acura's method of computing MILES or AVG MPG, I'm just speculating. You're right, it is a weak method of calculation, maybe too weak to be a credible theory. But I've been sitting on a couple 30min HF telecons, engine off, ignition on even though the owner's manual states that HF is enabled 30min after ignition off. One hour of sitting in a 12 hour tank of gas is consistent with an 8% error on AVG MPG.

My theory is probably crap, but I am going to try your suggestion just for fun .

DMZ

The Accord Nav system has had the instaneous MPG indicator along with a trip computer that gives substantially more info for at least 3 years now. TL buyers pay $$$$ more and every right to expect at least the same or better functionality, NOT LESS !!

Acura belongs in the dog house on this one.

reisb

We may have a winner.

Filled up today. Stats below:
26 MPG
36 AVG MPH
394 Driven
11:36 time
15.9 gallons to fill

394/15.9 = 24.8 MPG
11.6 time * 36 MPH = 417.6/15.9 gal = 26.3 MPG

Now testing without any time in car while car off, my miles driven vs. time * avg MPH is within +/- 1 mile.

Stupid calculation by Acura

Anyway, it appears if you want accurate MPG info, don't sit in your car with radio on and engine off.