Chevy Impala Rental - Fuel Economy, Hypermiling, EcoModding News and Forum

Lazarus · 10-17-2010, 10:06 PM

I've have some traveling to do this week and since I don't have a car, rented one. They gave me a new Impala Lt with 800 miles on the odometer. The car is rated at 18/29. The tire pressures are set at 35 PSI. I'll have about 230 miles of highway (during rush hour on both ends) and then probably another 100 miles or so of stop and go in a large metropolitan city. It has instrumentation so I've reset everything when I picked it up. I'll give driving impression through the week. So far my 25 mile commute home was unimpressive as far as FE goes and it was a perfect day for ecodriving.

The car is very heavy, drinks gas on acceleration but seems to coast well from 45-30. The cruise RPM at 55 mph is around 1600 RPM. It is a flex fuel vehicle but it appears to be running E10 with the numbers I'm getting. The inside is very quite and comfortable but the blind spot on the left hand side is really bad and a deal breaker for me if I was going to buy(with those number would not be on my list). I'm 5"10 so maybe not an issue for taller or shorter folks.
Everyone is welcome to play guess the mileage game on the final MPG when the trip is over. No mods only ecodriving and no engine off except at lights. Keep in mind I'm not as sharp as I used to be and the car is not really broke in yet.

Angmaar · 10-17-2010, 10:30 PM

35mpg+?

rbrowning · 10-18-2010, 10:09 AM

I drive an 06 model of this car with the 3.5 engine and the tires at 40PSI. My commute is 55 miles (all highway) each way and generally get 32 unless I run the A/C in the morning to keep the fog off the inside of the windows. BEWARE, this car will out coast most cars and it is REAL easy to overtake someone faster than expected

.

Unfortunately the first 10-15 miles really kills your MPG, I'm not sure if it is in "rich" mode or just what but it doesn't seem to be temp induced, 80F afternoons are as bad as 60F mornings for the first 10 miles or so.

PS: If you find some descent seats please let me know. My Chiropractor is almost done with the new addition to his house.

Lazarus · 10-18-2010, 08:49 PM

Quote:

Originally Posted by rbrowning

I drive an 06 model of this car with the 3.5 engine and the tires at 40PSI. My commute is 55 miles (all highway) each way and generally get 32 unless I run the A/C in the morning to keep the fog off the inside of the windows. BEWARE, this car will out coast most cars and it is REAL easy to overtake someone faster than expected

.

Unfortunately the first 10-15 miles really kills your MPG, I'm not sure if it is in "rich" mode or just what but it doesn't seem to be temp induced, 80F afternoons are as bad as 60F mornings for the first 10 miles or so.

PS: If you find some descent seats please let me know. My Chiropractor is almost done with the new addition to his house.

That funny I was thinking the same thing about the seats after only 2 hours on the drive down. I think your comments some it up nicely. The coolant temps seem to come up quickly but even with it in the normal range it takes a while for the FE to get going.

I'm surprised how hard it is to pull good numbers out of this car. With it's coasting abilities I would think 40 MPG would be doable but I'm not even close. I was surprised when I got in crawl traffic on the interstate that it's has good FE from 20-35 mph with the coasting abilities. If you did not have to accelerate it would do great. It appears that just punching it seems to be the best method. I either get 7 MPG with hard or 13 MPG with easy acceleration. The AC just kills the mileage. Cruising and turning it on and off see a difference of about 12 MPG on the instantaneous meter. Who knows if that accurate.

rbrowning · 10-18-2010, 09:11 PM

"Who knows if that accurate."
I won't speak for the instantaneous readings, but the average readings are remarkably good. So far I have never had the computer disagree with the pen and paper by more than 1 MPG and that could have been my filling style variation or the particular station (parking slope makes a difference.

On the seat issue I may have inadvertently found some help today. I noticed that most of my problem is my left hip. Tonight I wedged my flexible lunch cooler between my left knee and the door. It is really hard to say if that was the solution, but one less vicodin tonight seems like a good thing to me! I will be arranging for something more permanent for continued testing.

Lazarus · 10-24-2010, 02:37 PM

Well ended up with 31.7 on the gauge. The car is pretty furstrating to work with. I think you could do alright if it was just used for highway but the city portion just kills it. Hard acceleration seems to be the key followed by the great coasting ability. Ac is an absolute killer, 10+ MPG showing on the console read out. Whoever designed the seats must of not sat in them. Very uncomfortable.