Alfa Romeo Giulia Forum banner
1 - 20 of 39 Posts

·
Registered
Joined
·
103 Posts
Discussion Starter · #1 ·
Is there any 'cluster' (or other) indication when cylinder deactivation is happening?

Seems like that might be a useful piece of information.
 

·
Registered
Joined
·
249 Posts
Does anyone have a white paper/technical reference for how cylinder deactivation works in our cars? (I know....I'll Google it too). I'm curious as to how it works. Doed is shut off one side of the engine? Does it alternate as you are driving? Etc.
 

·
Registered
Joined
·
1,726 Posts

·
Registered
Joined
·
249 Posts
Awesome stuff.....thanks for sharing.
 

·
Registered
Joined
·
1,815 Posts
All this added complexity (and a double ECU!!) to gain a few miles per gallon.
Who buys a Quadrifoglio to save gas? Also, I don't like the uneven component wear.
An engine without this feature would have been simpler, lighter and cheaper.
 

·
Registered
Joined
·
315 Posts
I had to chuckle as I went through the manual....the notes on the turbo are funny.

Auto part Automotive engine part Automotive super charger part Automotive starter motor Engine
 
  • Like
Reactions: Emozine

·
Registered
Joined
·
3,313 Posts
"to gain a few"

I doubt it even does that, as it only happens in low load situations where not much fuel would be used anyway - the vehicle has to be running with essentially no boost from the turbo, so it's functioning as a low compression economy six.
like with the start stop thing, these "advancements" are very complex ways to squeeze a tenth here and there to meet draconian standards - which with luck will be trumped by revised standards.
of course CA could prevent any manufacturers and the public from benefiting from loosened CAFE rules.
 

·
Registered
Joined
·
49 Posts
All this added complexity (and a double ECU!!) to gain a few miles per gallon.
Who buys a Quadrifoglio to save gas? Also, I don't like the uneven component wear.
An engine without this feature would have been simpler, lighter and cheaper.
I also agree with this but i can only imagine it's 100% necessary as i don't think they would waste money and add complexity if they didn't have to. Yeah they could of done it differently but what's to say you don't just step on a load of other companies patents and associated fees.

Very interesting document that has been shared here, thanks for sharing jwq2
 
  • Like
Reactions: John_K_348 and jwq2

·
Registered
Joined
·
1,726 Posts
...
Very interesting document that has been shared here, thanks for sharing jwq2
Something I found on internet, actually, I think originally from someone on this forum ;)

Looking at the boundery conditions for the cilinders to de-activate, it probably doesn't happen very often anyway in normal use ;) ;
only when coasting
 

·
Registered
Joined
·
1,308 Posts
All this added complexity (and a double ECU!!) to gain a few miles per gallon.
Who buys a Quadrifoglio to save gas? Also, I don't like the uneven component wear.
An engine without this feature would have been simpler, lighter and cheaper.
True but it’s nice to max out fuel economy on long interstate cruises and subsequently extend range. It’s interesting to see the conditions required for activation. So under around 77mph looks like the upper speed limit. Do the related Ferrari V8’s do bank deactivation as well?
 

·
Registered
Joined
·
765 Posts
Don’t some jurisdictions tax differently based on the fuel economy of a vehicle and don’t manufactures have to comply with minimum fuel efficiency threaholds to avoid gas guzzler taxes? This is why there is an A mode. I have used it a few times on my QV on the highway when running low on fuel. It worked well at 120-130 kmh cruising speeds.
 

·
Registered
Joined
·
206 Posts
Also gives some insight into the used strategies, see f.i. (page 216 onwards)
Fairly complex ;)
I use this a fair bit on road trips. I had no idea that there were specific conditions in addition to selecting A mode. Or that depressing the accelerator (such as to overtake) would restore it back to 6 cylinders temporarily. Great info, thanks for posting!
 

·
Registered
Joined
·
3,600 Posts
Thanks guys! I am pretty sure it kicked in during my drive to PA in February. I will look at the manual now, but I suspect a good indicator on the dash will be watching the efficiency meter tape on the bottom of the screen in A mode. When you pass the white dot and fill the tape to the right of it, this is probably when cylinder deactivation engages. Disappointed to hear it's single bank, as with a 6 it could do 2 + 1 in alternating "forks." Maybe the vibrations were worse? Our engines DO have a hefty balancer.
 
1 - 20 of 39 Posts
Top