Hello I am new to this forum and was drawn here because I have a question about the i-VTEC engine. I have a brand new 09 accord 4DR EX V6 automatic. My question while cruising at 65MPH when the ECO light comes on what should my rpm on the tachometer be at on average? I have noticed that there is no change on the rpm from just before the ECO light comes on to when it does. Shouldn't it show some kind of drop?

I don't have an Automatic but my guess is it shouldn't change much. Sure the engine drops a couple cylinders but you still stay in the same gear and that ultimately determines what RPM your engine spins at.

I don't have an Automatic but my guess is it shouldn't change much. Sure the engine drops a couple cylinders but you still stay in the same gear and that ultimately determines what RPM your engine spins at.

Yup, RPM should not change at all if you are cruising at the same speed.

the eco light changes nothing, it is merely an indicator light letting you know your car is currently operating in eco mode. before the light comes on, you are already in eco mode (in your situation, for however long it takes the electronic relay to signal the info to your indicator light :) you understand?

at 65mph, I am guessing your rpms should be around 2000. however, I have the i-4, so others will tell you exactly where they stand. my i-4 hits about 2000 rpms at 65mph in 5th.

On my V6 I remember it being between 2000 and 2500 at 65mph...and no RPM change when the ECO light turns on - the engine is spinning at the same speed, just has some cylinders deactivate.

Hello I am new to this forum and was drawn here because I have a question about the i-VTEC engine. I have a brand new 09 accord 4DR EX V6 automatic. My question while cruising at 65MPH when the ECO light comes on what should my rpm on the tachometer be at on average? I have noticed that there is no change on the rpm from just before the ECO light comes on to when it does. Shouldn't it show some kind of drop?

There is no RPM change because the engine is only shutting off the necessary cylinders to meet the demands of both acceleration and fuel savings. The engine monitors the "engine load" and applies the appropriate power, hence activating or deactivating the cylinders.

Here is what Honda has for their brief description on VCM:

Variable Cylinder Management™ (VCM®)The Accord Sedan’s V-6 features the latest generation of Variable Cylinder Management™ (VCM®) technology. This system can activate and deactivate the engine’s cylinders as needed to meet the demands of both acceleration and fuel savings. When maximum torque is required, all six cylinders are firing. During steady cruising speeds , VCM shuts down one bank of cylinders. In this mode, the audio system’s Active Noise Cancellation™ (ANC) function generates out-of-phase sound waves to cancel out any undesirable noise that may be due to the harmonics of 3-cylinder operation. As cruising speed increases the engine moves to a 4-cylinder mode for extra cruising power. To help keep engine vibration from reaching the cabin in every mode, active engine mounts automatically adjust their firmness to help absorb energy. The transition between the three operating modes is nearly seamless and goes unnoticed by the Accord’s passengers.