Chrysler is in a sad state these days, but it is not beyond saving. Much has already been said about the unlikely alliance between Chrysler and Fiat, though little in the way of new products have been announced. We know Fiat plans on bringing the 500 to America, and there was the Chyrsler/Lancia Delta concept car. But nothing else we can wrap our eyes around.
Fiat has more than just small cars though. They have their own version of variable valve timing, called MultiAir. This system can increase power by 10% while decreasing fuel consumption by up to 30%. It was recently revealed that the MultiAir technology will be making its way into Chrysler cars.
These MultiAir engines come in many sizes, from the Fiat’s 1.4 liter engine to a larger 2.4 liter. The MultiAir system works by controlling the valves and determining how far to open them and thus how much fuel is injected into the engine. Cars with MultiAir tend to see a 3-4 mpg improvement in fuel economy and a 10-20 horsepower bump.
Fiat had already announced that Chrysler would be building the 1.4 liter version for the Fiat 500. I had assumed that Fiat would be bringing this technology to Chrysler cars eventually. What I would really like to see though, in addition to the MultiAir system, is the return for the Multiple Displacement System. This short lived system, available only on Chrysler’s HEMI V8 engines, would shut down four of the eight cylinders at highway speeds. Why couldn’t this be applied to smaller engines as well? Maybe I am hoping against hope, but I think these two systems combined would be quite the one-two punch for fuel economy improvements.
Source: The Motor Report | Image: Fiat
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“What I would really like to see though, in addition to the MultiAir system, is the return for the Multiple Displacement System”
Shutting down un-used cylinders will only result in extra friction which causes the energy savings from this to be less than one might expect. Part of what makes an engine efficiency is valve area -vs- friction. Which is why FIAT’s Multi-Air works, combined with significantly reduced pumping losses which also incease the engine’s effiecency.
A turbocharged engine is effectively a variable displacement engine…without the frictional losses from shutting down un-required cylinders.
FIAT’s Prof. Rinaldo Rinolfi began work on this before 2000, this work was stopped during the FIAT-GM years when GM would not spent a red-cent on developing this technology. Development resumed after FIAT removed the GM’s influence and soon after Sergio Marchionne became CEO of FIAT.
“What I would really like to see though, in addition to the MultiAir system, is the return for the Multiple Displacement System”
Shutting down un-used cylinders will only result in extra friction which causes the energy savings from this to be less than one might expect. Part of what makes an engine efficiency is valve area -vs- friction. Which is why FIAT’s Multi-Air works, combined with significantly reduced pumping losses which also incease the engine’s effiecency.
A turbocharged engine is effectively a variable displacement engine…without the frictional losses from shutting down un-required cylinders.
FIAT’s Prof. Rinaldo Rinolfi began work on this before 2000, this work was stopped during the FIAT-GM years when GM would not spent a red-cent on developing this technology. Development resumed after FIAT removed the GM’s influence and soon after Sergio Marchionne became CEO of FIAT.
Exactly like the VTEC engines in Honda and the Toyota. Whatever you name it, it’s still variation in the valve timing to produce more power/fuel economy. Except in Fiat. Look forward to when it’s in every vehicle. Just like when the majority of vehicles used Dual Overhead Cams in place of single cam shafts.
Exactly like the VTEC engines in Honda and the Toyota. Whatever you name it, it’s still variation in the valve timing to produce more power/fuel economy. Except in Fiat. Look forward to when it’s in every vehicle. Just like when the majority of vehicles used Dual Overhead Cams in place of single cam shafts.
A a 3-4 mpg improvement in fuel economy doesn’t exactly sound like a gamechanger…
A a 3-4 mpg improvement in fuel economy doesn’t exactly sound like a gamechanger…
It’s a step further than VTEC as it’s variable lift as well as variable timing. It allows the elimination of the throttle butterfly valve, a significant cause of efficiency loss in conventional engines.
It’s a step further than VTEC as it’s variable lift as well as variable timing. It allows the elimination of the throttle butterfly valve, a significant cause of efficiency loss in conventional engines.
Chrysler wouldn’t be Chrysler if the engines are efficient. In fact, efficient Chrysler engines are not possible- this would violate the laws of the universe.
Chrysler wouldn’t be Chrysler if the engines are efficient. In fact, efficient Chrysler engines are not possible- this would violate the laws of the universe.
“A turbocharged engine is effectively a variable displacement engine…without the frictional losses from shutting down un-required cylinders.”
That’s true, but most turbocharged engines require premium fuel due to the higher effective compression ratio (actual compression ratio + turbo-compression).
Till now, I think it’s been thought that the price of the turbo and the premium fuel requirement makes it impractical for an economy car. Now that “green” is in, and people are paying premiums for hybrid luxury SUVs and such, it’s probably time to rethink that.
On the multi-displacement engines, GM and Honda have/had V6s with that feature (GM also has V8s with it), but I don’t know if it’s practical to do it in an I-4.
“A turbocharged engine is effectively a variable displacement engine…without the frictional losses from shutting down un-required cylinders.”
That’s true, but most turbocharged engines require premium fuel due to the higher effective compression ratio (actual compression ratio + turbo-compression).
Till now, I think it’s been thought that the price of the turbo and the premium fuel requirement makes it impractical for an economy car. Now that “green” is in, and people are paying premiums for hybrid luxury SUVs and such, it’s probably time to rethink that.
On the multi-displacement engines, GM and Honda have/had V6s with that feature (GM also has V8s with it), but I don’t know if it’s practical to do it in an I-4.