Sunday, October 21, 2007

Flaw in Chevrolet's Average Economy

What do you do on a long journey to keep yourself occupied? Well here's an idea. Test the Average Economy part of your on board computer to see how well it works. Take a photo of it while driving at 70MPH.

I was bored. There was a long downhill coming up so I reset the Average Economy at the top of the downhill and coasted down. I'm driving a Tahoe which is not the best in fuel efficiency. Would you believe that Chevrolet do NOT expect their Tahoe to get better mileage than 99.9 MPG? That's where the calculation (or at least the display stops) so I was unable to determine exactly how fuel efficient I was being by driving downhill.

So how long do you think it will be before GMC realize this mistake and fix it on their cars? With hybrids becoming more and more popular they're going to have to address this. It's really a question of whether or not they know about this bug in their system.


Anonymous said...

I drive a Toyota Prius (hybrid) and the best mileage you get to see on the display screen is also 99.9 MPG. So my guess is that GMC will leave it the way it is for now.

Guy Ellis said...

Maybe they all buy that bit of technology from the same manufacturer?

Anonymous said...

I doubt it. I’m sure Toyota makes its own display (in Japan) and GMC must make its own as well (probably China).
I just think they decided to stick with the 99.9 MPG because the average was never going to be higher than that. I average 50 MPG. Not bad, but I heard of people doing “funny” stuff to get the Prius to do better (like going on neutral downhill!! and making up to 70). Anyway, the good news is that the 99.9 MPG might change soon. In 2009 or 10 Toyota is launching a new Prius that will make 100 MPG! So we could see display screens with lots of digits very soon

Guy Ellis said...

That's how I got the Tahoe to read 99.9 MPG - by coasting down a hill. Not in neutral but not using the gas either. I reset it at the top of a long hill. First it hit 70 and then later 99.9 MPG.

I'm very impressed with the mileage that you get. Other people I know with hybrids get around 40MPG. I'm guessing that you have a light foot on the gas?

Anonymous said...

Ah, so you’re one of those…
The main reason for my good mileage is that I drive a lot on the express way (averaging 55 MPG). I try to start and finish my 28 mile commute early so I don’t get stuck in traffic. It is smooth sailing most of the time driving at speeds between 60 and 69 MPH. However, the gas I save cruising goes out the window once I hit the normal streets bringing me back to 50 MPG. At this moment I have driven 310 miles averaging 52.2 YES!!
I do let go of the gas pedal sometimes, especially when I’m getting close to a light, but the streets are pretty much flat, so I never dive downhill like others :)