My new 09 PDK got 28 mpg at over 70 mph on trip from MA to NJ in normal mode. Great, except it liked to stay around 1500 to 1800 RPM in 7th all the time, which I consider Lugging.
Do we trade off mileage for possible reduced engine life, because of possible lugging at low RPM.. I've always considered driving at 2000RPM minimum with my 6 speed.
Am I just being crazy, should I expect that Porsche engineers, in their infinite wisdom, deem 1500RPM as fine for the new engines?
Now at 1700miles, screw mileage, using sport, keeping revs at 20000 or above, Just questioning..

 

I'm sure someone with far more knowledge then I will chime in, but I always thought lugging to be load dependent. That is, it's not just dependent on the RPM, but how much work you're trying to do at that RPM. For example, the amount of work that needs to be done at idle, is far less then the output of the engine at it's idle RPM, therefor the engine does not lug in that situation. Likewise at 6000RPM when you're trying to accelerate. If you were trying to accelerate a tractor trailer carrying a solid lead trailer, it would be lugging at any RPM since the amount of work attempting to be done is more then the engine can produce at any given RPM.

The transmission automatically kicks down when it needs to, so I assume the work produced at 1500RPM in 7th gear is adequate to cover the work needed to maintain a 70MPH speed. I could be completely wrong tho for all I know.

 

+1 Correct. It is not lugging if the car is cruising under no load. As long as the transmission kicks down a gear under load then it's ok.

 

Thanks guys, just seems weird based on past 6 speed experience! :>)

 

It should be noted that Porsche added that 7th gear ratio specifically for fuel economy while cruising on the highway. It was never intended to be used as an accelerating gear. Since I don't have a PDK to test with , does it kick down to 6th as soon as you put your foot into it?

 

kicks down instantly.. or if you push pedal all the way to "kick down" mode.. it will drop to like 3rd/4th and haul ***..

trust pdk, at least until you can pronounce it in full perfectly.

 

If you go easy it will go to 6th, if you kickdown and you car has sport chrono package, it goes automatically to sport plus mode (it is described like this in the internal Porsche book), which at 65 mph will drop from 7 to 3rd gear and you will be close to 100 mph in a very short and loud time...

It's really weird the first time, the rpm builds up for a brief period of time before the clutch put the gear on, so once the 3rd gear drops your rpm is about 4500 rpm. Once it drops, it's a rocket and given that is using automatically the sport chrono setup, it will hold the gear at hand for as long as you keep your foot on the gas, changes happen close, if not at, the redline.

 

Normal auto walks the fine line of "lugging" . It is boring and dull and activating the kick down is a nuisance . It's for that reason why I only use normal auto in gridlock traffic where it's ideal .

Moderate speed with occasional stop and go get manual mode (sport) .

Highway speed I use sport auto with overrride .

I switch often between the modes .. sometimes in the same drive .

 

You know, I have noticed that. It almost feels like a turbo lag; you hear the engine revving up, you don't really go anywhere, and then all of a sudden you hear this growl and you're catapulted forward. If I'm about to pass someone, what I'll usually do it give the throttle a quick press down, let it kick down a few gears, and once it has and I'm ready to pass, just floor it. I find the lag of going straight from normal mode, waiting for it to kick down, and then hitting the power to be a little lengthy. Yet another reason to always drive it in sport or sport plus.

 

I feel the same way. What I'm trying is dropping 2 gears and just go, the torque is abundant so there is no need for screaming out loud in 3rd gear, unless one feels like showing how nice the new LED taillights look like as it passes by...