garyw90

I have a 2017 Stingray, M7. I am curious about the effect of v4 mode on the engine. When I am in Economy mode, there is sometimes what I would characterize as a bump when the engine switches from v8 mode to v4 mode. What is happening when it does this? It there some mechanical movement, such as the cam shaft? Also, when in v4 mode, does the engine always run on the same set of 4 cylinders, or does it use all 8, but only 4 at a time? Is there any harm in using v4 mode?

Vegas1500

eboggs_jkvl

Active Fuel Management (AFM), which shuts down the LT1’s firing cylinders from eight to four by disabling the valves to the cylinders. When AFM initiates, the engine turns the 6.2L V8 into a 3.1L V4, shutting down cylinders 1, 4, 6 and 7, and firing only cylinders 8, 2, 5 and 3 in that order.

Otherwise, the complete firing order is 1, 8, 7, 2, 6, 5, 4, 3.



2, 4, 6, 8, Passenger side from front to rear.
1, 3, 5, 7, Driver's side from front to rear

Elmer

Grand Slam

The lurch from V8 to V4 seems to be normal for M7's. V4 to V8 seems to go smoothly.

4thC4at60

I found the lurch up and down to be so annoying that my first time going into V4 was my last - 79,000 miles and averaging more than 30 mpg for the entire 79,000 miles... why would I go back to V4? To gain another 3 MPG? Four?

orca1946

Did you add the range unit?

Jaykoh-Z51

I have an M7. I kinda think of the bump going from V4 to V8 is like an afterburner lighting off.

I do use it but only on long trips and level roads. I also notice that if I cruise in 5th instead of 6th (60-70mph)..theres more available torque even in V4 in 5th to prevent as much switching. 5th in V4 will give a little better MPGs than V8 6th gear.

But honestly....it'd be hard to REALLY notice the difference unless you're doing long drives in E. I'm only in E on long trips...otherwise it's T S or W given the conditions.

Drive on....

cberistain

nicely done.

krwunlv

^^ what he said.

budgreen3564

~Stingray

What does Weather mode do that is not in all the other modes? Traction control is traction control, right?

Jmhornz71

I have a M7 and have never put the car in eco and never will for goodness sake its a Corvette not a Spark you want mpg buy the spark. If you set the car for sport tour or track it wont go into V4 with the M7 .

Dif

In Weather mode all the nannies are more sensitive and intervene a lot sooner than the other modes.
Most notable is reduced Throttle response.
Not that it cannot be defeated with heavy throttle, but it definitely makes it a lot harder to lose control.
I use it in the rain or wet roads, and don't really notice the reduced throttle.
Just to see how well it works, I tried a few times and it takes a lot more to get tire spin or the rear end to kick out.
The car is definitely more stable in Weather mode and I really like it when needed

bearphoto

My M7 will never be in Eco mode. I did not buy this thing for it to sound like a rice burner. Lucky for M7 owners the manual trans car will not go into V4 unless the car is in eco mode. Autos will go into V4 in all modes unless you put the shifter into M.

Jaykoh-Z51

I would use W or Track PTMwet when it was wicked cold and I still had summer tires on. Helps then too.

jimmbbo

It also keeps the car from yawing more than about 30 degrees when skidding under power.
Spring Mountain has a great demo of how it works

sjw91

I tried eco mode on my M7 for the first time on a trip last month. Averaged 28.5 mpg in V8 on the way up. On the way back, I put it in eco and averaged 29 mpg. It went in and out of V4 smoothly, but it's not worth it for 0.5 mpg.

AmmoVet