an08HHR

I have to disagree on that. Come to a hill and the cruise will down shift in order to maintain the set speed (automatic tranny). If the cruise is off you can regulate the gas pedal so that you will lose speed but the tanny will not down shift as soon or at all, depending on grade and length of the up grade you are on.

a76marine

I have always argued that as well...

Cruise is great for maintaining a certain speed, but cruise cannot determine what is best for the hilly terrain or slower traffic that is coming up.

02z28

right, but cruise control is your friend. i think a lot of cars have it setup so that when cruise is engaged fuel trims are leaned out substantially.

also, as far as shutting off the car, unless you're waiting for a bridge or a 5 minute traffic light, there are open loop tables in the pcm that will automatically richen the mixture upon startup for a set amount of time even if the engine is warm so depending on that mixture & how long its set to stay rich its usually not worth it for any short amount of time

Clevelandhhrss

If anyone wants to kow why i'm really doing this....

The quote above is exactly why.

I want to ppprrooovveee what is real and what is just hearsay.

Look at my mileage.....can YOU do better with cruise????

Try it and see....you will answer your own question :)

Clevelandhhrss

I am loving this already......

An experiment is bringing of all sorts of opinions...

And in the end we will have learned alot.....

What you say is true....but after a cold start up. I know nothing of the tables for A/F. I dont need to........ just as the first person do discover that the earth is round never saw the earth from space.

I get 2mpg out of my garage....for .3 miles....then after a mile I'll be up to 40mpg.......If I stop my car, turn it off, and then turn it back on (assuming its still hot), Ill get 40mpg right out of the gate.

Try it and see.....

Also check out the mileage gain by using idle to get going versus the gas pedal after a cold start up. Those first .5-1.2 miles will yield 3 TO 4 TIMES BETTER MILEAGE. Quick shift from 1 then 2 then 3 ...4...5 in like 75 feet. No gas, stay way away from the gas pedal. You will hit 25+mph in no time on flat ground. I have to brake before cutting into traffic from my jobs parking lot ....and i never even came close to touching the gas. If not ...be prepared to see 2 or 4mpg...ouch.

Clevelandhhrss

Yes cruise is for maintaining speed. I studied this in Process Control in my junior year. My prof was explaining how difficult it is to control reactions (reactors, chemical procesess, etc), and he used cruise control to demonstrate a GREAT and ACCURATE system. However the control is for speed...not load. And cruise from what i believe (could be wrong here ...i am theorizing) is a feed forward design. So cruise prepares for a hill by making sure you can climb it to INFINITY. I'm in ohio, the elevations rarely change more than 150ft at the extreme in a single hill. So I can use "load control" versus "speed control" to "rollercoaster" over small hills. That is where the boost--- i mean vacuum gauge comes into play. That is also why drive in a speed range of 50-65 depending on the hills and their length...cruise will hold it within 1mph like 63-65. I want to crest the hill at 55 and be rollin the bottom at 65 or more in a 60mph zone.

I will use cruise control on the same routes that i drove without on my next tank so i can plot the differences. I can already tell you that i might get home from work 2.5 minutes quicker (whopee?) but i will lose minimum 3 mpg.

i did get 39.2 mpg on my first day leaving work.

calgaryhhr

As in interesting side note to the cruise control discussion here. I use cruise control on every stretch of flatter road that requires a constant speed. I'm very diligent in shutting it down when approaching hills so that I can manage the RPM's myself in the HHR.

This weekend my girlfriend and I went out to the lake and took her new (2008) VW Golf (City model) and I was driving back with the cruise control on. On a few of the mid sized hills I was amazed to see that the VW did not drastically increase engine speed to go up the hill. The RPM's actually dropped up to 200 RPM and the car slowed about 5km/h (2 mph or so.) On the larger hills it did increase engine RPM's to maintain speed but it's much more gradual than the HHR. I was really shocked to see that it actually maintained engine load and let the speed drop a few km/h.

Clevelandhhrss

I do believe that some (maybe in the past but not currently) that some cruise control systems have been set up this way. Some even allow for a greater mph range to accomidate flat but rolling terrain. My hhrss is not one of these vehicles, and I have been noticing that not only does it pick up rpm too soon, it lets go too late. I didnt drive yesterday, but ill post todays in the evening. Im stil holding 36mpg.

mach01

Right now I am hypermiling with my 2007 HHR LS. I am using 6.9 liters per 100kilometers which equates to 40.93 mpg city/highway combined. My tires are @ 40 psi cold.

Clevelandhhrss

Manual/automatic?

40 psi cold...wow, im under that on the hottest day, on the highway.....
what is the terrain like near you
length of average drive from cold start , to stop.
Octane?
Any tricks or techniques being employed.
What speeds? the posted limits and what you actually drive.
A/c?
Window open?
The 2.2 should do better then my 2.0, any mods on your car?
Current odometer?
Etc.

Help, teach, learn contribute.
Many here get in the low 20's lol. Help them out.

Have you really gone more than 600 miles before a fill up? That would be sweet!