5th Gen Subaru Impreza Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
44 Posts
Discussion Starter #1 (Edited)
Now that we have all the specs for the 2017 Impreza, it appears that the cylinder deactivation feature that was proposed for the Impreza concept is NOT yet implemented.

However, I have come to the realization that cylinder deactivation might not be such a good thing after all. I am not an auto mechanic or know anyone who is, so the concept of using less cylinders to save on gas sounded great. After digging into this for several days and reading about the technology behind it and issues that other car manufacturers have had with it, it sounds like cylinder deactivation is not worth it at all.

One site I found compared the MPG difference using cylinder deactivation for the vehicles below and the increase in MPG was one only 1 City and 2 Highway when in fuel saving mode. Both of these used a 6-cylinder engine.
Toyota Sienna
Honda Odyssee

There are also many reports of oil leaks and higher repair bills for engines with this technology. I was going to wait for the 2018 Impreza before researching this, but now I am leaning towards getting one without this feature due to the problems it can cause. I can definitely see the benefit for an 8-cylinder engine using 4 to save on fuel, like the corvette, but for a 4-cylinder, would it even be worth it?

Can anyone offer any first hand experience using a vehicle that used this feature and if they had problems?
 

·
Registered
Joined
·
163 Posts
Higher repairs bills would only make sense to me because it is a much more complex engine that you're working with. That being said, depends on the severity of the repair being done. For a 4-cylinder come to think of it, it really doesn't seem like much of a difference especially when you point out that minuscule mpg difference considering that's basically a margin of change that will happen due to driving habits. Not significant enough.
 

·
Registered
Joined
·
308 Posts
For some people it'll be a big deal.. one because it's one of those selling features that sounds super advanced and people love that. Another thing being some people are really hyper milers and something like 2mpg is enticing for em'
 

·
Registered
Joined
·
43 Posts
Most car manufacturers have perfected cylinder activation for years, with few problems. They work well for larger displacement powerful vehicles, such as pick ups, SUVs and sports cars which, due to their abundance of power, can easily function with half their cylinders temporarily sleeping. However, for a 152 HP car with at least moderate air resistance, not sure that going to half power would be something that would be able to be used except for going down hills and/or driving on level interstates with little traffic.

I am not going to miss cyclinder deactivation on the new Impreza, but enjoy it and use it some of the time on my powerful sports car.
 

·
Registered
Joined
·
229 Posts
Last I recall in the early 2000's BMW had it on a few vehicles. I know the E46 M3 was one of them and that came out in 2003. Likely other high output/high performance BMW's had it, 7 series should be one of them.


Usually BMW and the like are at the forefront of tech like this. So that's over a decade its been in the works.
 

·
Registered
Joined
·
163 Posts
I've heard they've had issues across different manufacturers for excessive oil consumption and other issues. Chevy more notably however. Some people reported lifter issues as well.
 
1 - 6 of 6 Posts
Top