RPM's & MPG - 986 Forum - The Community for Porsche Boxster & Cayman Owners

thstone · 10-06-2011, 07:27 PM

The should be a speed vs rpm chart for your car in the Technical Data section of your owners manual for both tip and manual transmissions. That will tell you the expected speed in any gear at any rpm.

My 2.5L 5-spd is doing a bit over 70mph at 3,000rpm in 5th gear and I average about 21-23mpg in steady freeway driving (70-85mph).

Here is the chart from my owners manual:

DenverSteve · 10-07-2011, 12:13 AM

The answer to your question is - yes - your transmission is an overdrive transmission.

stephen wilson · 10-07-2011, 02:37 AM

What are your other vehicles that run lower RPM? Engine size will affect gearing, my Integra turned 3500 RPM @ 75. I'm also guessing a Porsche isn't geared (pun intended) towards economy.

alemar · 10-07-2011, 06:09 AM

Thanks for the replies. It's good to know this car is performing as it should. All my previous vehicles turn about 1600 rpm at 60 mph. This includes my wife's '05 Camry, and my '08 Sport Trac Explorer (with v-8, auto trans). We get over 30 mpg highway on Camry and about 24 mpg with the Sport Trac with both running about 60 mph.

Boxster safely,
Alex