In a similar vein to the current discussion about downshifting on ice,
how do people feel about downshifting to reduce speed on hills? I’ve
heard 3 theories on this one:
- you should always downshift to reduce your speed when going downhill
as this reduces wear on your brakes and gives you better control.
- you should use your brakes to reduce speed when going downhill,
in order to reduce wear and tear on the transmission, which isn’t
really designed for braking. Also, this is more fuel efficient.
- with manual cars, you should use the engine for braking; with
automatics, it’s best to use the brakes.
Any theories?
-mattb
—
Matt Bamberger
Microsoft Corporation "Wake up to find out
Applications Division That you are the eyes of the world"
…uunet!microsoft!mattb
In article <50…@microsoft.UUCP> ma…@microsoft.UUCP (Matt BAMBERGER) writes:
>In a similar vein to the current discussion about downshifting on ice,
>how do people feel about downshifting to reduce speed on hills? I’ve
>heard 3 theories on this one:
[first two deleted]
> – with manual cars, you should use the engine for braking; with
> automatics, it’s best to use the brakes.
Since the manufacturers recommend putting the car in a loewr gear
(for a manual) rather than braking – I guess the tx will not be affected.
I guess that with an auto, the transmission would just upshift to the
highest gear and then start slipping. Would a lockup torque converter help
here? But then, why do manufacturers recommend putting the tx into "2"
or "low" etc?
____________________________________________________________
/ / /
/ Shantanu Ganguly / Dont even think the opinions /
/ gang…@cbnewsm.att.com / expressed here have anything /
/ gang%by…@aloft.att.com / to do with my employer….. /
/___________________________/_______________________________/
In article <50…@microsoft.UUCP>, ma…@microsoft.UUCP (Matt BAMBERGER)
writes:
> - you should use your brakes to reduce speed when going downhill,
Using the brakes in a long downhill run is *dangerous*, because the
brakes may overheat.
Several things could happen, either of them is sufficient to almost
completely loose braking force on the affected wheel:
– "fading" (apparently the friction between red hot brake disks and pads
are less than satisfactory)
– vapor lock due to boiling brake fluid
– grease in the bearing melts and flows onto brake disks or rotors
I’ve experienced the two first ones, luckily not in very dramatic
circumstances.
Anund Lie
In article <1990Feb13.083735.28…@idt.unit.no> an…@idt.unit.no (Anund Lie) writes:
+ - vapor lock due to boiling brake fluid
Does anyone know whether brake fluid or water has a lower boiling point?
If water, than this may help rid the system of water. If fluid,
nevermind.
=============================================================================
Paul Blumstein | "The Democratic System is the worst system to have–not
Citicorp/TTI | counting the other systems" — heard on the radio
Santa Monica, CA +———————————————————-
{philabs,csun,psivax,pyramid}!ttidca!paulb or pa…@ttidca.TTI.COM
DISCLAIMER: Don’t believe everything I hear or anything you say.
> Now, I’m sure your suggestion wasn’t serious, but I can imagine some poor
> fool getting the wrong idea. I’ve always driven a stick, and it was the
> first time I’d downshifted with an automatic. Figuring the lowest gear
> out of three (automatic) would allow a higher speed than the lowest gear
> out of four or five (stick), I threw it into low at about 30 (hmmm…I
> guess that advice about not skipping gears while downshifting is good
> advice).
Years ago I had a Cougar XR-7 with automatic transmission. The users
manual was quite clear on this point: "Do not drive more than 70 MPH in
low gear, or 90 MPH in second." I always thought that was a misprint
—–
jeffa sans 7.2 liter 10 MPG gas hog
DOT 3 brake fluid is mostly ethylene glycol which has a higher boiling
point than water. Also water dissolves in glycol, so you can’t separate
glycol and water by boiling. TO get water out of a brake system, you need to
replace the fluid.
Brent H. Besler