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Originally Posted by slownugly
Hey more power to ya but my 20 year old technology currently outperforms current technology in the fuel mileage region. My fiances car has cam phasers and can only return 32mpg. 35 if im driving. You are def correct in the longevity. I'm seein cars at my shop that have 150-200k miles on them and the valve covers never been off. Nothing wrong with that. But on the other hand I'm starting to see variable valve timing codes come up.
Probably the earliest cam phaser used is the 2.0 zetec. That is used just for egr imitation. Ive been to classes on cam phasing and variable valve timing so I know how it works. I'm just saying I'm not impressed In the least. When they start getting in the 28:1 and higher afr range I'll be sure to edit my post. I'm more impressed by pgfpros work with his work on his talon. 9 second in the quarter mile and 50+ mpg capability. THAT'S impressive.
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You must compare apples to apples.
Most of the "econo - cars" I have seen are much bigger and heavier than the Metro's and Civics of 20 years ago. The Dodge Dart II's, the Chevy Cruz and the Ford Focus all seem to be around 3000 pounds and still they get 40+ MPG. Their aero is marginally better than the econo cars of the 90s but the real thrust of the package is still buyer bling. Cut out the fat on a Dart II and I have no doubt it will hit 50 MPG. I've owned several llittle Hondas and Metros and I can assure you, I'll never own one again. I'm too old to be beat up like that. Noisy, rough and cramped for my six foot frame.
If you look at the situation in Ton*MPG, you can see that late model cars are actually quite efficient as a package. The only issue is that they weigh a ton! Not all the added weight is useless bling as the structural design as well as the added safety of side airbags are worth a few hundred pounds of mass. And remember, this current crop of econo cars doesn't use lean burn in EPA
trim. But, in a few years they will. Some may have HCCI or PCCI combustion technology. Some may have advanced clean diesel Tech or hybrid diesel injection. They may have a combustion engine not discussed yet. And they may become lighter as aluminum and composite structural assemblies become advanced enough to be used in mass production situations.
My point is, if you took today's production car technology and applied it to yesterday's light-weight econo cars, 50 +MPG would only be the starting point.
And pgfpros work is impressive. He, along with several others, have added much to this forum's knowledge base in the difficult area of engine mods. It is simply beyond the capability of most people for many reasons. But, his research is simply that - research. You are comparing a research vehicle to a production vehicle that has a ton of restrictions applied to it's design parameters.
The best way to compare engine efficiency across time and space is still BSFC ( brake-specific fuel consumption ). Can you produce power with as little fuel as possible, and can you adjust your gearing and chassis load to maximize the time you spend in your BSFC sweet spot? That is the essence of constant velocity ecomodding.