I'm very curious how consistent these vehicles are.

I would like to know at 2k rpms your MPH

When I'm on cruise at 2k rpms I'm right at 75mph
factory 3.55LS with factory 265 70 17s.

Engine rotation to Wheel rotation is solid except for the torque convertor. I would expect to see pretty consistent numbers in common vehicles, however who knows?

 

I've seen some variation too regarding this subject so began paying attention to it last week while driving home on a 200 mile trip. At 2000 RPM, my speedo says 72 miles per hour.

I also observed a disproportionate ratio of increased RPM to increased miles per hour........such that a 10 % increase in RPM does not yield a 10 % increase in miles per hour. Example: 10% RPM increase (2200 RPM) equal speed of 77 miles per hour (an increase of only 7%). Obviously, this explains all the complaints about declining fuel economy at faster highway speeds. It appears that best fuel economy will be achieved below 60 miles per hour.

What do you think?????

 

fuel economy drops as speed increases are also due to wind resistance increasing. Ever hang your head out a window at 30 mph and feel the gentle breeze? Try the same thing at 90 and feel the wall of air pressure that your engine must overcome!
Simple physics man....

 

fuel economy drops as speed increases are also due to wind resistance increasing. Ever hang your head out a window at 3 mph and feel the gentle breeze? Try the same thing at 90 and feel the wall of air pressure that your engine must overcome!
Simple physics man....

 

LocoScrew,

Tested my S'crew tonight. 2000 RPM gave me 76 MPH on a level highway. Windows and roof had no effect, nor did the A/C.

 

Go to my Photo Albums, check out the Bragg Smith Driving School

I have been to Bragg Smith twice, first time in 1996, driving C-4 Vettes. Second time in 1998, this time we had our choice (being alumni) of the new C-5's or Camaor Z-28's

I' HIGHLY recommend a vette owner attend the classes.
Learn what your car can really do, Flat Out.
(hint) a C-5 can't do much that a Camaro Z-28 can.
I let my Son use the C-5 and I used a Z in ***** out last day of class racing. He couldn't pull away from me.

http://photos.yahoo.com/jeff_east

or

www.bragg-smith.com

or

http://www.edmunds.com/ownership/dri...6/article.html

 

XTruky,
Now I know what she can get me for Christmas!
Always wanted to do that...

later