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Multi-Displacement System

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Old Jul 22, 2010 | 03:00 AM
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Default Multi-Displacement System
Does it turn on at a certain mile per hour? or RPM?

Lets say the truck is cruising at 80mph with five people inside will MDS kick in?
 
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Old Jul 22, 2010 | 06:58 AM
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It's possible if there's minimal load on the engine, like going downhill.
Jim
 
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Old Jul 22, 2010 | 08:47 AM
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My MDS kicks in at 30 mph and normally does not come on after 75 mph.
 
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Old Jul 22, 2010 | 10:29 AM
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It has a mind of it's own. Mine has kicked in at 80 mph before. Depends on the road conditions, how light or heavy your foot is and other factors.
 
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Old Jul 22, 2010 | 10:30 AM
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There is an algorithm that MDS follows. It is primarily based on engine load but there are vehicle speed restrictions (like below 15 or 20 mph) for NVH reasons. It will not come on at idle.
 
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Old Jul 22, 2010 | 10:33 AM
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Kinda off topic but i have been wondering. how does the MDS work, does it alternate between which cylinders it turns off? If not, is it wearing 4 cylinders excessively?
 
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Old Jul 22, 2010 | 03:11 PM
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same 4 are off...that's why it has to be a light load, so it doesn't cause excessive wear.
 
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Old Jul 23, 2010 | 12:23 AM
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I believe it just shuts off the fuel to those cylinders. The pistons would still be moving so it would still wear about the same.
 
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Old Jul 23, 2010 | 01:17 AM
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Spark plugs still fire to maintain cylinder heat.They claim no wear differences between cyliners.GM uses a similar system.
 
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Old Jul 23, 2010 | 01:18 AM
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Originally Posted by hounddogg
Spark plugs still fire to maintain cylinder heat.
so how we saving fuel if the plugs are firing?
 
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