Tippy

It is not hair-splitting, it is real World.

NNH

+1
I have 85k on my car, and I hope to put at least the same again before I need a new motor. Cruising in 6th is just one of the things I do to prolong engine life.

Paul 996

Seriously, stop and ask yourself why you are doing this? Seems that every noob at the track wants to impress their instructor with their downshifting prowess. Instructors are quick to discourage this activity btw. Are you slowing the car down with each downshift approaching the corner or something (hopefully not). Approaching a corner you should be braking to reduce the cars speed and then rev match/downshift into the appropriate gear for the speed that you just slowed down too.

-Paul

Benjamin Choi

real world what? instead of throwing out false claims, show us something like a car that resulted in an engine failure due to driving around in 4th gear on the freeway.

enjoy

NNH

Every engine has a lifespan. Partly it's the number of hours (which is what they measure for aircraft engines). Partly it's the number of revolutions which each cause a tiny amount of wear. So cruising at lower revs is one way to extend the life of the engine.

To back up Tippy's statement that higher gears extend engine life, here are two overdrive manufacturers and an article on overdrive, all of which state that overdrives (ie higher gearing) extend engine life and reduce wear.

Overdrive article
Ford overdrive unit
Tremec 5-speed add-on

Tippy

False claim? I highly doubt. I could back the claim up for days, just read Simons (NNH) post above.

Engine failure? Probably not. Will revving an engine unecessarily with an existing problem send it to the grave quicker? Why yes.

Tippy

Ben - let me give you an acronym:

R uins
P eoples or P orsche
M otors

JimB

I'm with Ray on this although it's different in different corners. Frequently the right thing to do is to just leave the clutch in and quickly run down through the gears. The 996 shifts great using that method. Just jumping from 5th (or whatever) to 2nd or 3rd will frequenly make it very hard to get into gear after the box gets hot. Likely not an issue on the street.

At Road America's T5, as mentioned by Ray, the fastest way into the corner is to hit every gear dropping the clutch in each gear. (sometimes I'll skip 3rd) It's a steep downhill you enter in 5th and turn in in 2nd. Dragging the back a little really helps settle the rear end and slow the car. BTW, this is my favorite track and my favorite corner.
Jim

jasper

So far on the street I regularly skip gears both on the way up and on the way down. As an example, when I pull out of the sidestreet by my house onto the main street, it's downhill, so I go first to third, and ofen to fifth after that. No point going through through second and fourth with a cold engine and gearbox. Similarly, If I'm toodling down the road in sixth gear, and I need to pass slower traffic, I rev match it down to fourth and away I go.

My opinion - On the street, skip gears all you want. It saves wear and tear on the arms and legs as well as the machinery. You ain't gonna hurt nothing on the street by skipping gears.

Now the track - I haven't done a track day yet with the six speed - my first is coming up in 9 days. In my old 5 speed 911 though, I'm with Paul - brake to the speed you want, match it into the gear you need, and you're done. If the track or corner, or whatevere doesn't warrant it then why do it - unnecessary wear and tear in my opinion. As far as gettingthe box hot and trouble shifting - it was never a problem with my 911. You have to double clutch of course.

springgeyser

+1 U beat me to it.

RPM= Ruin People's Motor.

JimB

Jasper,
FWIW I skip gears shifting up on the street all the time.

When you get your 996 to the track try downshifting as Ray and I have suggested. Don't let the clutch out in each gear. Just run through the gears on your way down. You might find you like it.
Jim

Benjamin Choi

rpm aka driving

1999Porsche911

My engine stalls if I cruise at less than 4000 rpm.

Riad

Saying you're on the highway in 4th is half the picture. How fast are you going?

You can hit 70mph in 4th gear a@ 4k RPM - that's fine.

If you're doing 85 - not so much. I usally keep the car between 3-4k RPM while on the highway, whatever gear I'm in that puts me in that sweet spot is were I'm going.

pszikla

Riad!
As I mentioned in my first post, it's about 60-65 mph and I guess that you put the word's "sweet spot" to my subconcious reason for cruising at the rpm where hitting the throttle makes the car launch while howling like a banshee!