I still have not yet passed the 2k mile mark on my HHR, and have already posted this:



I did this driving 55 mph on the highway, with the A/C on. for most of the drive.

On the subject of A/C, I played with the system to see if it behaved in the same manner as my Impala used to. I turned off the A/C at the switch, and then turned the system to recirculate. As I hoped, this does cycle the A/C back on, but acts as an "economy" mode, cycling the compressor at the minimum level possible to keep the interior set at the desired temperature.

This figure was netted going up from an altitude of ~3500 feet, over two 7,000 foot plus (Raton and Monument on I-25) mountain passes, and settling in at 5280 ft in the Denver area.

 

I got 38 mpg from the DIC while in the Rockies last month. I thought this was pretty sweet:



Most I dared to go was about 425 though.

 

Mine was showing well over 600 miles on the DTE screen after I filled the tank this morning. This however has been quickly erased with a city run to get the front windows tinted.

 

I'm curious, since my experience with the DIC proves it to be only a guide, what was your mileage figured mathematically between fill ups?

 

Mine is creating a pattern of displaying ~.8 mpg lower than calculated. This is the first mileage computer that I've had in my vehicles that has done this. Others have always been high.

 

Will the AC trick work even when its hot in the car or do you have to cool the cabin first?

 

I have seen the same results, but my DIC shows about 1 mpg higher than when calculated. I also lost about 3 mpg when i went from 16" to 18" wheels. I know average around 29 mpg.

 

I simply put the system on recirculate, leave the A/C switch "off", and let the climate control do it's thing. The A/C compressor will cycle on and run until the cabin has cooled down. Once this occurs, I'll then see the engine going into fuel cutoff mode more often on downhill grades (99mpg on instant screen). If the compressor is on, you'll see the 60 - 80 or so mpg on the same downhill grades.

 

Seriously, I hope you guys are as concerned about watching the road while your driving as you are watching the DIC and being concerned about if the A/C cycles so you get that extra 1/2 MPG from your car.

It scares me when I'm on the road with people more worried about things in their car than the actually control of the vehicle.

 

What is there to worry about? The entire extent of this effort was to simply push the recirc button, and turn the A/C "off" (light off on the switch), and then drive the car. I actually keep mine on the instantaneous mileage screen, set the cruise, and go. You should check your gauges often when driving. The picture you see in my original post was taken while parked in my folks driveway. If you want a distracting video game dashboard, drive a Prius. I have over a million miles of driving experience under my belt, so I think I know what I'm doing.

No, I do not advocate driving and staring at the DIC constantly.