Interesting Mirage Quirks!!

[Cani Lupine]

I just noticed my intermittent wipers are speed sensitive. It slowed down significantly when I was stopped, then sped up again when I moved. I had it on the first dash mark on the selector.

[El Kapitan]

Here is the reason why it does not slow the car down until it hits idle speed. It is incredibly difficult, if not impossible to prevent the car from nearly dying if it were to allow the rpms to drop down that low before allowing the car to coast. By kicking out of decel mode at 1200 rpms, it gives the computer a bit of wiggle room to adjust the idle.

For example, if the computer were to allow the rpms to drop to 800 before taking control over the idle, and if you had the A/C running, the headlights on, and the windshield wipers going then that rather large load on the engine could make the engine stall or stumble really bad if the rpms were to drop say 400 rpm. Whereas by taking control over the idle at 1200 rpm, with the same above circumstances, it gives the computer a little wiggle room where if the rpms were to drop by 400, the motor would still be running fine.



A rather large part of the computer programming on any car is devoted to comfort. Smooth transitions, decreased vibrations, and great driveability are put ahead of fuel economy and power.

yeah, i suppose that makes sense.

[El Kapitan]

I'm no expert, but here is what I envision is going on when you decelerate to a stop. During deceleration, there is no fuel going to the engine so it is not firing at all. Then before you stop, the engine has to be re-started from the momentum of the car. Also, during deceleration the CVT would be in its highest gear ratio to allow coasting. Just before stopping, it has to shift to its lowest gear ratio to be ready to take off from standstill.

when in the "D" setting, it feels like DFCO does not engage. it just coasts to the best of its ability in a high gear ratio, seemingly unaware that you want to stop instead of coast (unless there is something wrong or different with my specific car). when in "B", there is definite engine breaking and DFCO. as mentioned before, it switches off engine breaking in the "B" setting at about 1200 rpm. i notice that you also drive a CVT. do you use your "B" setting often? if so, what are your impressions? also, if you are coasting and you take your foot off the gas, does DFCO engage or does it just coast, gradually losing speed? my car , in "D", just coasts, gradually losing speed. if i am on a downhill grade, the car begins to accelerate.

[MiMi]

I'm not a good one to ask because where I live there is generally fairly light traffic. Changing traffic lights can generally be anticipated and I can do a gradual stop. Even if I had a manual transmission, I would just slow down and then stop while in 5th gear. Again I'm no expert, but I believe that the fuel is cut off as soon as you remove your foot from the pedal. I've used B setting about 2 times in 20,000 km. Deceleration on a grade is another question. Recently I was trying to see if it was only the angle of decline that determined the gear ratio for deceleration, or if braking at the same time affected it. I didn't come to any conclusion so I have to try it some more. Anyway, I'm very happy with the CVT, but it does take some learning so that you know how it will react in various situations.

[El Kapitan]

only 2 times? i use the B almost every stop light. different driving styles for sure.

[Laila]

Whats the difference in coasting in neutral to stop and using the B? Is there a fuel economy difference?

[El Kapitan]

good question. i don't know the answer, but i'd imagine that there is not too much of a difference in fuel economy, with an oh-so-slight bias in favor of using B when used in the correct fashion.

as for the difference in coasting, try it out. when you're coming in to a stop light and are down to about 35 mph, shift it down to B. it will wind up to about 3500-4000(ish) rpm and then use the unwinding to brake the car. it's similar to the feeling when you downshift in a manual transmission. don't forget to shift back to D before you start going again or the car will wind out when you hit the gas.

[81.Chevette]

I'll post this in its own thread, but since there seems to be a lot of knowledge here...
I have the FAST key. Is there any way, via programming or brute force, to allow me to leave the car running, with the keys in my pocket, and lock the doors? I'm a delivery boy, and that would be EXTREMELY helpful.

[91cavgt]

I'll post this in its own thread, but since there seems to be a lot of knowledge here...
I have the FAST key. Is there any way, via programming or brute force, to allow me to leave the car running, with the keys in my pocket, and lock the doors? I'm a delivery boy, and that would be EXTREMELY helpful.

Later today I'll leave my FAST key at my house and I am going to try to drive away to see what happens. I'll post back my findings.

[JimInMichigan]

Later today I'll leave my FAST key at my house and I am going to try to drive away to see what happens. I'll post back my findings.

There is a post here I read, that someone had started their car during the winter (to warm it up) and put his fast key in his coat pocket. Went in the house, and not thinking, switched coats when he left, forgetting his fast key in the other coat. Car ran and when he got to where he was going, he turned it off. Of course, the car wouldn't start when he tried to leave. Also posted, the dash flashes a light warning you the fast key isn't in the vehicle, while running. As for locking the doors, I'm not sure. I do know on mine, the car beeps several times warning you that the fast key is not in the vehicle, if you try to lock it. I didn't pay attention if it actually locked the car ( salesman was showing me the features ).