Elite Status Quest with My "New" '99 Accord

[antrey]

After living about a year with only one car in the stable, my situation changed necessitating the purchase of a new vehicle. I had to purchase a vehicle within a period of 2 days and was unable to find a manual vehicle that met my requirements. A base Pontiac Vibe 5spd was sold before I could get to it. I settled for a 1999 Honda Accord LX Auto (4spd) and didn't have much hope with respect to hypermiling but have been pleasantly surprised with my initial results. Hondas seem to make great hypermilers in all guises. My first tank yielded 36.9MPG which is over 139% of combined EPA. I soon came to the realization that Elite status is very much within reach for me with this vehicle. I need to raise the average to 39.75MPG for elite status. The first tank was done with 44psi in the tires for most of the tank with 46psi for the last bit. I generated a speed vs fuel economy graph from 45mph to 70mph with the tires at 46psi and an extra 100lbs of weight in the vehicle besides driver:



The current tank is almost finished and thanks to the addition of the scan gaugeII, tires up to 46psi for most of the tank and 48psi near the end, silicone sealant around the lights, and the removal of the rear spoiler (air brake) it looks like I will eek out an over 39MPG tank; mind you this is according to an uncalibrated scan gauge reading:



As expected, the rear spoiler was acting as an air brake and the following chart shows a 2.5% improvement in FE at 70mph (not that I normally drive that fast, just exaggerating the effect):



Unfortunately, the rear spoiler was apparently a poorly installed aftermarket job and the paint underneath was damaged. I'm leaving it off regardless. It wouldn't be the first time a hypermiler sacrifices looks for FE just ask basjoos . I'll put it back on if/when I sell it. The following are shots of the rear spoiler, damaged paint, and the headlights with clear silicone sealant applied:






Grill block and treatment of the rear wheels and wheel wells will soon follow:

[Skwyre7]

Nice graphs. What was your test run conditions? Distance, traffic conditions, etc.? Just curious...

[antrey]

The route is on a freeway access road near the city limit so the traffic is basically non-existent. The runs are between 2 and 3 miles long, I haven't measured it exactly, with cruise control on the entire run. Runs are made in both directions to compensate for wind and elevation changes. The route is somewhat hilly and does have some curves. A flater, straighter route would be better but there isn't a suitable flat road that is long enough to maintain 70mph safely to get a good average. Temperatures were in the mid 50's.

[kwj]

Antrey, what will you do as far as "treatment of the rear wheels and wheel wells"? Thanks for the tip on silicone around the headlights. I need any tip I can get to push my Aveo mileage up. I had a 90 Accord (gave it to my daughter) which is really a great car. But, the gas mileage (27-32) seemed to be limitied by the power that little 4-banger automatic banged out. It was a very quick car for the size of the engine (and I had no concept of hypermiling back then).

[antrey]

Originally Posted by kwj

Antrey, what will you do as far as "treatment of the rear wheels and wheel wells"? Thanks for the tip on silicone around the headlights. I need any tip I can get to push my Aveo mileage up. I had a 90 Accord (gave it to my daughter) which is really a great car. But, the gas mileage (27-32) seemed to be limitied by the power that little 4-banger automatic banged out. It was a very quick car for the size of the engine (and I had no concept of hypermiling back then).

All the holes in the hubcaps will be covered. I'll initially just tape over them but possibly silicone some more permanent plastic pieces to them. The rear wheel wells will eventually be covered over as in the stock insight (or old cadillacs ).

My initial tank as measured by the scan gauge was amazingly accurate. The scan gauge showed 13.7 gallons used and 536miles run with avg MPG of 39.2, manual values were 13.699 gallons and 536.0 miles (535.1 plus 0.9 mile I add to compensate for high speed FASing where the odometer is not running). I had added a -1.0% fuel correction to the scan gauge assuming a slight negative compensation would be required and it turned out to be spot on. I don't expect future tanks to be this spot on, I'm assuming it was a bit of a fluke.

Thanks to the Scan Gauge II I discovered the power of pulse and coast with an auto tranny and improved my driving without brakes technique. I also saw the first over 500mile tank I've ever produced from any vehicle. A 600 mile tank was easily in reach but I decided to fill up to check the SGII calibration. My avg improved more than 2MPG even though the 2nd tank was driven in more challenging FE conditions than the 1st tank.

[Skwyre7]

Antrey,

Nice tank!

[kwj]

Antrey, it looks like your "quick buy" Accord is a real keeper. Hope it serves you well for a long time (wow, almost 40 MPG with an automatic). Thanks for the additional information.

[jcp123]

Interesting...your Accord is about 5mpg behind what my Focus is capable of at 45mph, but as speed increases, my Focus' MPG performance falls off way faster than your Accord's. By 55mph, I'm already about 2mpg behind. Aerodynamics?

[koreberg]

@jcp
I would guess the gearing would have more to do with it. I just have a hard time believing that the focus would be that much less aero dynamic than an accord.

Usually my 4 cylinder cars are at around 3 grand at 55 where my v6 cars are usually about 2 grand which is the sweet spot for engine efficiency I believe. But i'm just guessing based on my limited experience with different vehicles.

[jcp123]

You must have had some super short-geared cars. Focus runs ~2k rpm @ 50mph, ~2500 @ 60, ~3000 @ 70, and I would venture to guess the Accord is relatively similar.