terryt5231

2005 TL with 91k miles

This morning I filled up my tank with Mobil 93 premium (and put a Lucas fuel injector cleaner). Then I pressed reset on the MID Trip Computer and the "tripometer", i.e. both at 0.

I drove 119.7 miles over the course of approx 2.5 hours. About 100 were highway miles, the rest were city. On the highway, I tried to keep it between 60-65 mph, with a few strong left lane passes (up to 75mph). The 119.7 miles reading was taken upon putting the car into PARK at the Mobil, again.

1. MID = average 29 MPG (attached pic)

2. Filled the gas again w/ Mobil 93 Premium. Put exactly 4.614 gallons. 119.7 miles divided by 4.614 gallons = 25.94 MPG


Assuming my simple calculation is the most accurate, then I'd like to say...Wtf, MID???

Anybody else find that their MID is off as much as 3 MPG?

Waltah

iTrader: (3)

im going to check mine at next fillup. problem is I drive my S pretty hard all the time.

I hate cars

Lots of threads out there on this.

Your calculation is probably off due to the pump shutoff point. Imagine it shut off slightly later giving you 1/2 gallon extra the last time.

119.7/4.1=29.2mpg

You need to average it over at least 5 tanks at the same station, same pump if possible and it will be much more accurate.

The car's ECU knows exactly how much fuel is being injected per revolution, it knows the total revolutions and the total miles driven. It is extremely accurate.

LaCostaRacer

I agree with IHateCars- the mid is extremely accurate. I have 4 years of data and it is almost always within 1-2 MPG of actual. I found that it usually understates the actual mileage so actual is slightly better.

terryt5231

Ok, I'm sold. I see what you mean re: inaccuracy of the actual pump. Will test a few more times...

SouthernBoy

"I hate cars" is right. The most accurate way to do a check like this is to do your fill up until auto-shutoff. Drive your car for you "test" miles or for your normal period until you need to fill up again. Then return to the same pump with your car in the same position, and fill up your tank to shutoff.

In this manner, your calculation will always be more accurate than the MID display because you will see the decimal fraction part of the mileage whereas with the MID, you do not since it rounds to the nearest whole number. I use my MID's mileage reporting as a guide and for that, it does a very good job.

Incidentally, I used this manual technique when my '04 manual was young for a work week of driving (five days), which was all through a small city and residential areas in light to moderately heavy driving. My car returned and average of 27.98 MPG for that summer week which is the best in-town mileage I have ever recorded with my TL.

AMUA6

iTrader: (7)

Man this guy is a book of awesome knowledge!

terryt5231

Lol! That's what I was gonna say. Either IHC is actually really knowledgeable in TLs, or he is the world's greatest bullshit artist.

darcar

I've been tracking my MPG carefully over the last year. The MID overstates MPG by 1-1.5 rather consistently. I've been getting slightly over 23 MPG overall with a mix of city and highway driving. 2008 TL.

SmileyOr

I've found it to be very close to what I'm getting at my pump checks.

I have reset it going up hills and downhills as well as level ground and the numbers look appropriate. From what I see when I reset it is that it only takes a short time/distance to get a reading. This means it's sampling quite often if not constantly. I believe it is constant

I also notice that if I am consistently conservative on the throttle my MPG can go up 3-4 mpg on a 100 mile trip. No passing, just sitting on cruise control at 60 mph compared to putting your foot into it passing 4 or 5 times on a trip over a twisty road before settling back down on cruise control. It doesn't take much to make a difference.

07 TL Type S

I hate cars

A little off topic but I managed 37mpg on the 4 hour trip from Vegas to Bakersfield. I was leaving on a Sunday and my ATM card had been cancelled because the replacement was in the mail. I had 1/4 tank and only a $20 on me. I hit the 15 and got in the truck lane behind a diesel doing 55mph. I stayed there until I was going down the baker grade and took it up to 100mph and coasted the entire 20 or so miles without touching the gas. It was a long boring trip but I was amazed at the gas mileage potential.

terryt5231

IHC - been wondering your opinion about this. I commute on a nice hilly, windy parkway everyday (http://www.nycroads.com/roads/taconic/). There are a few 2-3 mile hills which make for excellent coasting.

In my old car (Impreza), I would throw it into neutral and truly coast, assuming that this would increase MPG even more during those 2-3 miles down hill.

Question - Is it beneficial to put the TL into neutral during coasting? Or, on the contrary, are there potentially negative aspects to it? i.e. bad for tranny?

(Coasting, but remaining in Drive, I saw ">50" show up on the TL's MID yesterday)

I hate cars

If it's a long hill you will get better mileage with it in gear. In neutal, it consumes the same amount of fuel as it does at idle. In gear, as long as the rpms are above idle speed, the injectors are shut off so it uses no fuel at all.

mayday813

Keep in mind that 2005 TL's had a problem where the odometer reads high by 2 to 5%. Thus, your MID would overstate your gas mileage. Other years may have been affected too, I don't recall.

SouthernBoy

Both the 04's and the 05's were affected by this. Acura extended the mileage warranty by 2500 miles because of it (5%).