View Single Post
Old 04-10-2020, 10:00 AM   #40 (permalink)
smooth driver
Join Date: Jan 2019
Location: Toronto, Canada
Posts: 5
Thanks: 0
Thanked 0 Times in 0 Posts
Originally Posted by alcom View Post
Correction: 1,800-2,000 RPM at 100 KPH -- I was in a hurry and had 60 KPH on my mind when I wrote that.
I did a controlled run to map RPM against speed -- 100 kph on the expressway going out and 40 and 60 kph on city streets coming back -- light traffic, roads visibly flat no strong wind. Here's what I found.

Forester CTV -- 40 km x2 on cruise control
100 kph 1750-1800 rpm - expressway, going out
40 kph 1250-1350 rpm - city streets, coming back
60 kph 1250-1500 rpm - city streets, coming back

The bottom end for the CVT is just 500 rpm above idle. The wider variance at 60 kph is likely due to variations in road pitch. Engine torque curve is a factor. Even with variable valve timing, the sweet spot is likely 1500-2500 rpm. Maintaining momentum and keeping airspeed (i.e. resistance) down are at least as important as low rpm. The CVT will deliver lowest rpm for torque needs.
  Reply With Quote