trench

On the drive in to work I discovered an interesting feature of the car (C230K - manual transmission). There's an uphill portion on the exit I use, to go back over the freeway by way of an overpass. Traffic had stopped halfway up this incline and I noticed that on the slow crawl up to merge onto the other road that once the car is going from rest, it will maintain enough throttle without actually giving it any gas via the pedal to drive along without stalling.

Anyone else notice anything similar? All of the other manuals I've had would just shudder and die on an uphill without driver input from the gas pedal - of course, they're all relatively old - maybe all newer cars do this now.

Along similar lines, I read in the new Mercedes Enthusiast magazine that MB is working on some new brake features. One is an uphill assist. If standing still on an uphill road the car will maintain braking without pushing on the pedal. It releases the brakes once the gas pedal is pressed. Would make driving the manual much easier in San Francisco! The other feature would be used in traffic jams. If traveling under 25 and the feature is engaged the car will gently apply the brakes once the driver lifts his foot from the gas, eliminating the repetative back and forth motion. This feature sounds a little dodgy to me - unless it's combined with Parktronic to prevent driving into the back of the car in front of you if it stops more suddenly.

Cheers, BT

hokusbenz

my manual does this too. if i slow down enough in 2nd gear it will maintain a little bit of throttle instead of flat out stalling. it does this on flat ground too.

SoCal240/6

Most manual transmission cars will go up a slight incline in first gear without giving it any gas. I think it depends on the idle speed and the gearing.

The hill assist (puts the brakes on when you are on an incline so you don't roll back in a manual car). Subaru had that 20+ years ago!

mdp c230k

I've got the car to run in idle in 1st, 2nd, and 3rd gear on flat road without lugging the engine!

trench

Actually, what made me notice it was this particular incline is relatively steep for an off-ramp, the rise begins about halfway around (I'd say between 10-15% grade). The car had to be supplying some throttle (my guess isn't that this is exclusive for hills - just that the CPU provides throttle when ever it detects the motor is begining to lug).

My mom had a Suburu that didn't have this feature - but it had a handbrake, maybe they were mutually exclusive.

Cheers, BT

Nola

I owned a '96 Chevy Cavalier about 6 years ago that did this. It would go up a San Francisco-style hill ay my girlfriend's (now wife) parents house without so much as puting your foot on the throttle, even if it was loaded with four adults and their beach gear. I thought that was pretty neat, since I've tried it on plenty of other, newer and more technologically advanced cars. haven't tried it on my C230 (different city, no hills around).

Enze6997

How does it distinguish between idle on a hill and stalling on flat ground?


Does it just depend on having a running start?

20FHK02

when i was passing a huge speed bump around my hosue last night at a vey low speed i intentionally let off the gas pedal to see what will happen. amazingly the car automatically gave more gas to the engine while it was having tough time going up the bump. i know for sure because i saw the engine rev down then rev up and i also felt the push.

so i think if the load change is fairly gradual the computer will response and automatically give more gas to rev up the engine. but if, say, u let go the clutch too fast from a dead stop then the engine will stall because u don't allow enough time for the computer to response to the sudden load change.

Nola

Because this same "feature" was present on my relatively low tech Cavalier (less likelyhood of fancy computer work there), I think it has more to do with something purely mechanical than software related. It seems to do exactly what an automatic would do in the same conditions, short of engaging the clutch to prevent a stall.

raunen

I was pleasantly surprised the other day when I discovered the hill assist feature. No brakes, no gas, car doesn't roll backwards on an uphill.

My previous car only offered downhill assist .

Capt Nemo o2

Its merely because the car is computer controlled fuel injected. The copmuter says to idle at this engine speed, no less, no more. If you ease off the clutch (as opposed to just dumping it) the computer can keep up to maintain that engine speed. So once moving, as long as you are not in too high of a gear, the engine will idle in that gear.

SUNILP

my auto does this as well. Will not roll back

artur023

mine rolls =(!

tifosiv122

It's a shot in the dark, but a simple Gyro could tell the computer if the car is flat or on an incline.

Erik