Why no more lean burn??

[slownugly]

Rusty- so let me get this straight. If weight was taken out of the equation on a new gasoline non-hybrid to equal the weight of my 2000 lb vx then the return would be the same or superior to the lean burn technology? They are making new cars that are lighter and more aerodynamic and they still don't touch the vx. Speculation or educated guesses about a certain drivetrain in a lighter car is not enough to sway my opinion.

I have tested my vx with 650 lbs and mileage dropped 3-4 mpg from my average. (to 49mpg from an average of 51-53) That's about 2750lb curb weight. If I increased the weight to 3000 lbs I highly doubt it would drop below 45. This makes me want to try it. I'll drop a small book Chevy in the backseat haha.

[California98Civic]

Originally Posted by MetroMPG

My bad -- I referred to the expensive conventional 3-way cat. Thanks for the correction.

No sweat. You taught me something. Why shouldn't I experiment with this "second cat" at prices like these (~$40)? Would be good for the planet if it worked and might save my butt at my August 2014 Cali smog test.

[rmay635703]

Originally Posted by pgfpro

In the future I think we will see Stratified 'Ultra Lean Burn Engines" at 65:1 A/F ratios running "Gasoline Direct Injection" and "Spray Guided Piston Injection" in conjunction with new Turbo Charger technology in the forms of "Turbo Compounding Motor Generation Units Heat" and dual stage high-pressure/low pressure turbos systems.

GM has lead the field with DI, and guess what, they have done EXACTLY the opposite, trying to get as homogenious a mix as possible, again due to "emissions concerns" read don't want to mess with having better emissions equipment or fuel economy, just cheaper emissions and less hassle.

[user removed]

Honda claims the two valve ISDI engine can match the VX lean burn engine in efficiency.
Valves are offset with two plugs per cylinder. Personally I am a fan of transonic combustion technology, which highly preheats the fuel which ignites without spark when injected at ultra high pressures directly into the combustion chamber. You may see a combination of the ISDI configuration with transonic injectors, which could possibly pass the 50% efficiency threshold, maybe even 60% after considerable refinement.
Better mixture distribution will eliminate NOX emissions as far as regulated amounts, possibly altogether.

regards
Mech

[Randy]

Originally Posted by California98Civic

And if we can use the pricing at Majestic Honda as a guide, that Nox device (a second cat) is really cheap, about $40.

That's not the right part... it's the $660 or $1300 one. I think the $40 part is the converter cover like on this other parts site.

Honda still does lean burn when it can get away with emissions, like all their 40+ hp outboard motors.

[California98Civic]

Originally Posted by Randy

That's not the right part... it's the $660 or $1300 one. I think the $40 part is the converter cover like on this other parts site.

I'm not sure of that... the diagram you link only quotes one price for one CAT, instead of two as it should. It's true the pic points to what looks like a second downstream cat, but it does not list the price for the first. The site I linked offers both prices, one high and about what the page you linked lists, and also another price for a separate item that's about 40 bucks, and it labels that the price for the second cat. I don't know which is right, but I'm certain neither offers a completely clear answer. Lots of cats. But my apologies for distracting the thread from strictly lean burn stuff... cheers.

[Randy]

I had a cat efficiency code on my Insight, and eventually ended up buying an aftermarket cat… it seems like you can get the rear catalyst from Honda, but the front is only in a front/rear kit (at about $1k). This is a 2000 so it doesn't monitor the second cat.

The two prices were for different years: parts 18160-PHM-A00 vs 18160-PHM-A20. There's a third O2 sensor port on the later part, but maybe other hidden changes. My link only shows one year but your link shows both under diagram #5.

NOx absorber catalysts are pretty unusual, but they're basically the same as a normal catalyst. I think even the scrap value is more than $40. Although the parts place did label it "converter" the too-good-to-be-true rule of thumb applies here.

[cRiPpLe_rOoStEr]

Originally Posted by rmay635703

GM has lead the field with DI, and guess what, they have done EXACTLY the opposite, trying to get as homogenious a mix as possible, again due to "emissions concerns" read don't want to mess with having better emissions equipment or fuel economy, just cheaper emissions and less hassle.

Folks on the market for a new car are not willing to pay more just for the "eco" factor, or to deal with some complexity-enhancer stuff such as SCR/DEF, unless they feel entitled to brag about it like the stereotypical hybrid owners.

[Mad Adder]

Good thread going here.

I am also in the "not impressed" camp. My 84 SVO Mustang can cruise out nice fuel mileage in the low 30's, when I'm not spooling the turbo for fun. It will haul ass or sip gas, but not both, lol.

I cannot seeing paying the high price of the "eco" car until it bangs out impressive numbers. What I see on here from some of the older cars getting decent mileage makes me want to pay used prices to save money, then save at the pump. The other thing is the longevity of the new tech. Until it is proven, let others pay to be guinea pigs.

Power? I ran a low 10-sec 86 Mustang GT for years. Nothing will impress me now in that department, so I'm ok with slower and drive-able. My current car is a 92 Volvo Turbo wagon which gets 20-ish. I want 35+ out of the box and then search for more.

[MetroMPG]

Mazda says:

"If we want to dramatically improve fuel economy from here, the only route is through lean burning"

So says Mazda's chief exec for powertrain development, Mitsuo Hitomi.

Though he's talking about HCCI petrol engine development, not a "lean burn mode" in an otherwise standard engine.

Mazda engineers aim to eke the gains by cranking up the engine's compression ratio to 18:1, from a current level of 14:1. Higher compression tends to improve fuel economy because they can achieve the same combustion temperature with a leaner mix of fuel.

...

HCCI allows for more complete fuel combustion and lower nitrogen oxide emissions.

http://www.autonews.com/article/2014...on-skyactive-2