986 S vs 987 S Speed at 3k rpm

Had my son in-laws car for a week a few weeks ago. Got to drive from LA to Bay Area and back. About 350 miles each way. I noticed his 03 986 S 6 spd avg over 25 mpg and i was doing > 80 mph on I-5 and at times even faster. Note: I left LA at 2am Sunday Morning and hardly no cars on I-5 at that time. At 3k rpm speedometer was at 80 mph.

I was impressed with the mpg so I decided to take my car on the freeway and see what my speed is at 3k rpm. My car was only at ~75mph. 5 mph less than the 03 S. Explains whay my mpg is less than his. I'd have to do ~70 mph on flat roads to get >25 mpg.

I was wondering if any of you fellow Babblers can chime in on what speed are you at 3k rpm. 986 S vs 987 S.

I don't have an S, but the best mileage I've logged in my '99 2.5L was 26 mpg coming back from Tahoe (down hill). My normal daily driving, 80% highway and 20% street is 20 mpg... It's no Prius, but then again, IT'S NO PRIUS, so I guess I can't complain too much.

What's your speed at 3k rpm?

Best mpg i can get around here normal driving is about 17. Freeway's a lot better. Explains why I still drive an old Crx Si as my daily. Still gets 41 hwy and 33 mpg to work.

Are you basing this on indicated or real speed (using a GPS) as based on the 2003 chart that's attached you'd be doing about 72MPH @ 3K in 6th.

You can find similar charts in the Owner's Manual for each year and Renntech has many of them available online.

Tom M said:

Are you basing this on indicated or real speed (using a GPS) as based on the 2003 chart that's attached you'd be doing about 72MPH @ 3K in 6th.

Click to expand...

I agree with that. I am definitely not doing 80 (indicated or real) in 6th gear at 3k RPM. Nor am I getting more than 25mpg.

Milage

Disclaimer: This is only based on the on-board computer.

I have an 08, (not S). Around town milage sucks—17±. When I'm on the freeway, I've reset the milage computer and get high 20s. Usually cruising 70-75.

Last weekend my wife and I took it on its first Sunday drive. Went up over Sir Francis Drake, north on 1 to Point Reyes, Occidental, and Jenner. Great fun. Milage definitely not in the high 20s.

Man. These cars are small and slippery enough that they aught to be good for 30mpg on the highway. The Germans pay way more than we do for gas...I wonder why they chose such a narrow ratio spread for this transmission that causes such high revs at highway speed in top gear. My '04 R32 had silly-tight gearing like that and it never beat 26mpg either. I just sold an '09 Dodge Challenger R/T with the 5.7L HEMI and 6-speed stick (376hp and 4000lbs+) that would do 28mpg at 65mph while spinning about 1600rpm. This may be comparing apples to basket balls, but a Boxster is light and powerful enough that it aught to be able to handle tall enough gearing to run 2000rpm at highway speeds. You'd just have to be willing to downshift on serious hills is all...