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Posted on 03/24/2008 5:45:29 AM PDT by Uncledave
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The intriguing bit for me was the gent who invented a gizmo that he activates with a switch when he's traveling over 35 mph. He cuts the fuel to 1/2 the cylinders, and thereby increases his gas mileage to nearly double.
Obviously, passing power and hills would be more challenging with this activated, but can any engineering experts here comment if this is feasible and practical?
Please Freep Mail me if you'd like on/off
GM has had this for years, I think they had problems with it the first time around, the devil is in the details.
He cuts the fuel to 1/2 the cylinders
This isn’t new. The Big 3 have been working on this for years.
Cadillac had the V-8-6-4 engine in the 80’s.......
There are several new cars out now which more efficiently cut off half their cylinders, including deactivating the valves so those cylinders won't have to compress the air.
Either way, I want no part of it. Try pulling half the spark plug wires off your engine and driving to work. See if that is satisfying.
No, I want no part of that malarkey, nor do I want a hybrid with expensive and complex electro-mechanical chicanery. Give me a small, efficient four-cylinder diesel that always fires all its cylinders and gets 50 MPG.
Car companies have been working on schemes like this for years, including the Caddy V8-6-4, which was a disaster. More modern versions seem to work a lot better.
The 2009 Camaro has this feature built in.
Hell, I had a Jag that regularly ran on three cylinders. Don’t recall it helping the mileage any though...
Hell, Dodge HEMI’s have been doing that for the last few years, it cuts back to 4 cylinders when cruising.
I read not too long ago about a new experimental technology that allows conversion of heat directly into electricity.
It would be interesting, I think, if they were to apply that to the automobile. You could do away with the alternator, reduce the drag on the engine, and reduce the weight at the same time. Might also be able to reduce the size of the cooling system.
Unfortunately, the research is only in the “pure research” phase at this point. Probably by the time they get it ready for market, the gasoline powered engine will be extinct anyway.
Doesn’t the valet key for the Corvette do this by not allowing a parking valet to have use of all 8 cyclinders?
Oh Yeah! That was the one with Lucas Ignition.
The one with Smiths ran on four.
My 2007 GMC Sierra Crew Cab engine does this automatically. It senses when it needs HP and switches on the other 3 cylinders, or switches them off when it doesn’t need them. I find it looney that the media would consider this newsworthy since it has been around for a long time and now is virtually a standard on GMC trucks.
Yeah, and we all remememer what a stunning advance that was.
There are some things Detroit should buy up and bury.
Unlikely to double mileage. Making fewer cylinders work harder is more efficient than having more cylinders loafing - due to losses in heat energy and unburned fuel at the cylinder walls and heads of every cylinder which is working. These are marginal improvements, though, and only worthwhile to manufacturers who are doing everything they can to bump up their CAFE a mpg or two. Designing an engine with fewer cylinders to start with is even more efficient, because those cylinders that aren’t working are still generating frictional and pumping losses.
So yes, it does work in reducing fuel consumption, but not by anything like 50%
My parents had a Caddy in the 80s that did this and it did not work. My wife’s 2007 Tahoe has this feature and it works great.
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