Got 36 mpg on a 90 miles trip, cruise control at 70 mph. Mpg may be different depending on temperature, humidity, elevation, wind, weight in the car, and tires pressure.

 

48 mpg here...going downhill from Tahoe.

Wife took pics of the MID but I'm too damn lazy to post.

 

Only been averging 31.8 mpg on the highway, but I've been driving 65-80mph though.

 

so what do you get going uphill?

 

According to my spreadsheet it's usually off (high) by about 1.5 MPG.

 

If you hit reset on the MID, and you are going downhill, you can get like 200mpg average! Its awesome :p

 

I was just going to post something on this...went to get gas and I calculated 24.7 MPG (reset trip odometer every time I fill up) and the car claimed it was getting 27.3 MPG.

Doesn't anyone else think 10% difference is a little high?

Anyone know how the car estimates the MPG?

 

Mine has varied between almost exactly right to 2 mpg off or so.

My impression is that coasting (in which instantaneous mpg can be very high, almost "free") tends to throw off the MID on the plus side. On the other hand, steady highway driving produces a more accurate reading. I'll get confirmation when I go on a long trip later this year.

 

The gasoline pump probably doesn't automatically click off at the same point each time you fill up. I might trust the MID more than the pump. If it puts in another 1/2 gallon before it clicks off than it did the last time, your MPG will be lower.

 

Two weeks ago, I reached 40.7 MPG. Then I got home and after several stops, my average went down to 38.4. I was still stoked though.

 

When I gas up at Sam's Club, I can put in 1 1/2 extra gallon when it clicks off the first time. It takes a while to get the last 1/2 gallon in the tank. My record is 16.2 gallons in one tank. The MID was pretty close with under 20 miles till empty and mpg Avg before I filled up.

I've learned that day the DTE (distance till empty) is very accurate the less gas you have in your tank. Before that day, I always assumed I had a reserve capacity of 1-3 gallons when DTE was at zero.

 

This is just SWAG (Scientific Wild Ass Guess)

I think the MID calculates gas mileage according to the current driving conditions in that moment in time such as; actual fuel consumption, rpms (maybe), and current mph. The MID then calculates the average by saying “you are traveling at 65 mph and only using .025 gallons of gas per minute which equals 29.3 mpgs. The MID saves the data and then calculates the average with the past “snapshots averages” since the last MID reset/refill. The longer you travel since the last reset, the more consistent the readings and you have less “jumps” up or down in average mpgs. Then the MID uses this avg mpg data to calculate the Distances Till Empty (DTE) mileage (Avg mpgs X gallons in tank calculated by fuel gauge – reserve amount).

 

I've had mine over 40 MPG for short segments (like 20 miles), but usually settles to between 31 and 33 by the end of the tank. I'm only in the early stages of traking the error margin on the display, but so far the display is 1.75 MPG off on the high side (compared to the actual calculation when I fill up). My Civic was off an average of 3.1 MPG (measured over 60 tanks), again high. Must be a Honda/Acura thing.

 

I'm getting 23 mpg damit......

 

Since our odometers run fast (04-06 anyway, i guess 07 is accurate now?), I guess even our manual calculations are probably even a little optimistic

 

my 06 6spd/w nav , bought new in November 2006 has a very acurate odometer- when I go thru those speed checks on the highway, my speed is the same that shows up on them. I average 32-33mpg but it has been up to almost 37mpg. love the car. it has enough power for me. I gave up racing- not really (LOL)

 

Just got 38.1 for a 300 mile round trip from Colorado Springs to Breckenridge. Lots of climbing, but it evens out with lots of downhill as well...

 

That's pretty friggin' awesome.

 

Odometer, not speedometer.

 

Yeah, I haven't quite figured out the downhill thing. Worst case going uphill seems to be like 10-15 mpg, but downhill the MID pegs at 60+, almost like you get better overall if you drive uphill somewhere and then back versus the same distance on level ground (seemingly defying the laws of physics). However, I think I read somewhere that a gas engine is most efficent at lower RPM -- within reason -- and WOT, so maybe this makes sense after all.

Coasting to stops and downhill driving add hugely to mpg.

 

i just bought a 2005 5AT with 21,500 miles on it.

on the first 5 gallons of 91 octane shell vtec, I only got 20 miles to the gallon!
(street-freeway mix driving).

My 99 V6 Accord gets 22 (mix) on just regular unleaded!

could it be that the idle speed is set too high? currently its set to 750 rpm?

I thought I should add how I calculated it. I filled the also empty tank with Vtech
drove it for a few days and then topped it off again. I had done around 109 miles
and the tank took in about 5.5 gallons. which works out to about 19.8 miles/gallon.

 

Best thing on hills is to run a constant speed going up - enough to hold speed but not accellerate. The downhill part is easy.

In my Civic the optimum RPM was around 2200. In my TSX, I've observed that on a level road I can hold 50 MPH right on the 60 MPG mark and the engine turns about ~1800 RPM. At 60 MPH it's at ~2000. I'm thrilled this car is geared to go highway speeds very efficiently. The drag must be low too, as folks seem to go 70 and still get above 30 (wind resistance becomes your biggest enemy after 40 MPH). I'm taking a long trip at the end of the month - anxious to find out it does at 70-75 MPH.

 

I might suggest to look at a few things:
- Tire pressure (anything low?)
- How hard are you driving (quick starts, high speeds kill FE (fuel economy))
- Running high RPM before you shift? There are threads here that talk about the optimum shift points for economy (IIRC, around 3K rpm)
- How's the weather? Cold, rain, etc. all hurt FE

Driving style is probably the biggest issue with mileage. The car (tires, oil, etc.) are secondary. The gas won't matter - octane is relative to the needs of the engine compression ratios. However, using the wrong gas could hurt.

One last tid-bit would be to use the instant MPG display. When I first had one, I was amazed at how heavy I was on the gas and really didn't need to be. The guage will help teach you the right amount of gas to apply to hold speed. You'll spend more time in the 40-60 mpg range, and that will make a big difference. The basics are easy accelleration, hold constant speeds, coast more (instead of rushing to a stop), use the mpg display, shift at lower rpms. The idle speed seems just fine.

Good Luck!

 

Also, don't forget that the ECU is always adjusting. If the previous owner drove it very agressively then the ECU optimized itself for performance. Drive around cautiously, with fuel economy in mind, for a few days and then do your mileage test again.

 

The ECU is self-learning??? thats pretty impressive!

 

Its a non-navi so I don't have that luxury!

another thing that pops to mind is that I filled it up at another gas station. If the automatic pump-shut off was set differntly maybe I put in a little bit extra gas?

Plus my wife drove the car for 2 days. (whenever she drives my accord i get 19miles/gallon instead 22!) But its probably the jack-rabbit starts - they're always fun for the first few days ;-)

I see how it goes for the next days and report back.

 

Yup, I had a chance to fill up today and get right on the Interstate for a bit. After 12 miles, the MID indicated 36.5 mpg at the bottom of the ramp when I went back to city driving. Of course, now it's back to 28.5 or so, which is what it usually indicates get in mixed driving. (This is 6MT)

One of these days I'll get to take a serious road trip...

 

Actually, if you mean the MPG display, it's a non-navi thing (at least in the 06). I have an 06 non-nav, so I'm not sure if the mpg display is available in all year models. But it's one of the display options I can cycle through on my dash display.

Pumps will give you some variability for sure - if you want to minimize it, use the same pump at the same station. Forgot to mention that gas with an Ethanol mix(E10) will hit your MPG as well.

When I had my Civic Hybrid, I would get about 45 MPG. My wife would drive it for 20 miles, and it would come back at 40. For the 4+ years I owned the thing, I could not figure out what in the world she was doing to it. I suspected street racing for a while.

 

Update on the accuracy of the MID, I drove 80 for 250 miles of the tank in mountainous terrain...about 50 miles in the city... and another 160 going between 60 and 80 in the mountains again...the MID stated 32.3, calculations with a calculator after topping off the tank as much as I could showed 32.6 mpg. MID was actually under this time. I think the MID is very accurate and I get great gas mileage because the transmission always shifts around 2500 rpm and rarely on a freeway ramp around 3500. I have around 8000 miles on it now and I am starting to hear some noises..! I have driven it on a lot of bumpy roads though...

 

Not to take the thread off course, but I believe that the odometer and speedometer get their reading through the same system, so if the speedometer is fast, the odometer will also record slightly more miles...

I get about 21 mpg as well... i do way too much city driving. managed to get 34mpg (6.9 l/100km) one a couple of tanks, doing mostly highway...

 

I believe that the highway numbers published for the TSX are 31mpg for the 6MT, and 32mpg for the 5AT... the 1mpg difference would be a start, and it is probably magnified at higher speeds.

Even driving 75-80mph on all highway driving, I managed to get 31mpg over 1000 miles, when the car was almost new. I would expect I could do better now; I just need to plan a road trip that would be worth it!

 

Not necessarily when you're dealing with an all electronic system.

In my last car (Jetta), the speedometer had a deliberate +3 mph error (constant, no matter how fast you were going), but the odometer was razor accurate, less than 0.5% off.

I haven't checked the odo in my TSX yet, the the speedometer is spot on based on those radar/speed limit warning thingies.

 

Remember!! The TSX brochure bragged about the TSX having less CD drag than the NSX!!! Look at the great attention to detail with the underside plastic spoilers and cladding to control the airflow drag...

 

i never get that high no more i like drivin hard

 

You guys getting 30+ mpg is impressive. My last tank was 25 mpg and mostly highways. My car has 1300 miles, so I guessing it should get better over time.

 

The highest I have ever gotten on a tank of gas in the Acura is 36 mpg. On my 2002 TL Type S I got 29. On my 93 Lexus LS400 23...and on my favorite car I have ever had...1998 Lexus SC400 26 mpg. Verdict... I love the TSX but it will never be a V8 Lexus.

 

crazy i never get that high i must drive to hard

 

i average 24-26 mpg about 50/50 city/highway. I've never taken a really long trip to see if i can pull off over 30 mpg..but im sure it's possible. I've driven 398 miles on 13.5-ish gallons before...so i'm sure the 500 club is reachable for me.

 

For over 265 miles mostly all highway for the past 3 days I've gotten 32.2 mpg which it says on the navi info screen. I just hit the half tank marker.

 

Highest I ever saw in the TSX was just last week I got 36.4 mpg on the navi screen I was pumped going 65-75 mph at a steady pace.