EcoModder.com

EcoModder.com (https://ecomodder.com/forum/)
-   General Efficiency Discussion (https://ecomodder.com/forum/general-efficiency-discussion.html)
-   -   Zoom Zoom diesel (https://ecomodder.com/forum/showthread.php/zoom-zoom-diesel-20230.html)

botsapper 01-23-2012 03:16 PM

Zoom Zoom diesel
 
A more viable crossover to replace my present zoom zoom family bus. A handsome & distinctive sheetmetal sporting a Sky-D twin-stage turbo 4 cylinder with an available 6-speed manual transmission. Claims of 33/43 mpg economy from a non-hybrid crossover. Satisfying old school driving fun and decent pump avoidance numbers. Video Mazda CX5, Mazda Skyactiv D Turbo, vehiculo Mazda

UFO 01-23-2012 03:33 PM

Is this something available in the US now?

CigaR007 01-23-2012 03:34 PM

More on the SKYACTIV :MAZDA: VISION | SKYACTIV TECHNOLOGY | Mazda Spirit

I find it really interesting that Mazda decided to increase the compression ratio on the gasoline engine (14:1)

MAZDA: SKYACTIV-G | ENGINE | SKYACTIV TECHNOLOGY


meanwhile decreasing the CR in the diesel version MAZDA: SKYACTIV-D | ENGINE | SKYACTIV TECHNOLOGY.

Some very interesting information on that website regarding the necessary adaptations required by these engines.

botsapper 01-23-2012 04:47 PM

Initial specs on lowering the compression ratio of the diesel engine may make it more difficult to warm up and in colder climes may mean improper combustion ~ misfires. There is a exhaust gas variable valve overlap system, heating up the next sequential cylinder with hotter gases but still waiting for cold weather testing.
SoCalifornians would love this but Minnesotans will have to wait for real world reviews.

tjts1 01-24-2012 02:19 AM

Quote:

Originally Posted by botsapper (Post 281787)
A more viable crossover to replace my present zoom zoom family bus. A handsome & distinctive sheetmetal sporting a Sky-D twin-stage turbo 4 cylinder with an available 6-speed manual transmission. Claims of 33/43 mpg economy from a non-hybrid crossover. Satisfying old school driving fun and decent pump avoidance numbers. Video Mazda CX5, Mazda Skyactiv D Turbo, vehiculo Mazda

The 2013 gasoline burning CX5 is rated 26/32 mpg.
2013 Mazda CX-5
The cheapest gasoline around here costs $3.34/gal and cheapest diesel costs $3.99/gal according to gasbuddy.
A gasoline fueled CX5 will cost $0.128/mile city and $0.104/mile highway
A diesel fueled CX5 will cost $0.121/mile city and $0.0927/mile highway.

Throw in the additional up front cost of the diesel engine and what are you left with? If you're going to pay extra for fuel economy, it might as well be a hybrid which would bump up city mileage substantially while burning cheaper gasoline.

botsapper 01-24-2012 01:16 PM

Throw in the additional up front cost of the diesel engine and what are you left with? If you're going to pay extra for fuel economy, it might as well be a hybrid which would bump up city mileage substantially while burning cheaper gasoline.[/QUOTE]

...by replacing the biggest zoom zoom school bus, CX-9, would be an improvement.

Daox 01-24-2012 02:44 PM

Does anyone know why they've been decreasing the CR of diesels in recent years? I'd figure you want a higher CR to increase efficiency.

botsapper 01-24-2012 02:59 PM

Quote:

Originally Posted by Daox (Post 282079)
Does anyone know why they've been decreasing the CR of diesels in recent years? I'd figure you want a higher CR to increase efficiency.

The trend to lower compression ratios (Mazda Sky-D, 14:1) is the convenient engineering solution to reduce temperatures = required lower NOx numbers. The observed fuel mix had less hot spots and locally rich areas that creates telltale exhaust soot. Mazda also claims the lesser compression also mitigate heat expansions thus less friction. Improvements and gains in fuel economy. Less internal stresses also let the engineers to make the crankshaft, rods & pistons much lighter for beneficial weight savings.
Again the lower operating temps mean some difficulty in colder climes.

gone-ot 01-24-2012 04:11 PM

...here in Tucson, AZ, the diesel-to-gasoline cost ratio is 1.28:1 [$4.059(d) / $3.179(g)], so in order for diesel to come out "ahead," it had better get 28% better fuel economy than its equivalent gasoline-powered counterpart...which means >51MPG!

...and, that's NOT considering any other cost "uppers" such as the higher "going-in" cost of the diesel engine versus the gasoline engine.

CigaR007 01-24-2012 04:21 PM

Oddly enough, diesel used to be cheaper than gasoline, at least where I live.

sendler 01-24-2012 04:32 PM

That's a crazy,radical piston. domed with a cavity. Lots of extra surface area. But Mazda says it wastes less heat by keeping the flame contained in the cavity.

tjts1 01-24-2012 04:36 PM

Quote:

Originally Posted by Old Tele man (Post 282096)
...here in Tucson, AZ, the diesel-to-gasoline cost ratio is 1.28:1 [$4.059(d) / $3.179(g)], so in order for diesel to come out "ahead," it had better get 28% better fuel economy than its equivalent gasoline-powered counterpart...which means >51MPG!

...and, that's NOT considering any other cost "uppers" such as the higher "going-in" cost of the diesel engine versus the gasoline engine.

Same in California. The numbers I was quoting from gasbuddy are in Seattle where the gap seems to be slightly smaller but not by much.
Quote:

Originally Posted by CigaR007 (Post 282098)
Oddly enough, diesel used to be cheaper than gasoline, at least where I live.

When most of the developed world replaced their old gasoline cars with diesels, that all changed. The US is a net importer of crude oil and gasoline and a net exporter of diesel fuel. If this trend continues, the diesel passenger car doesn't have a future.

gone-ot 01-24-2012 06:29 PM

...yeah, same here! I can recall it being 89.9 a gallon when gasoline was $1.50-$2.00 range.

botsapper 01-24-2012 07:39 PM

Quote:

Originally Posted by Old Tele man (Post 282118)
...yeah, same here! I can recall it being 89.9 a gallon when gasoline was $1.50-$2.00 range.

It turned the corner, after 2003-04. US fed requirements to reduce sulfur increased refinery costs & raised the retail prices. Our Euro friends still pay comparatively less for diesel than petrol, even though they are twice our US costs. Some bean counters have an alternate explanation, because of the slowed economy, decreased US driving AND more efficient gas-powered vehicles, demand and prices decreased while the truck/diesel usage is stable and prices regularly increased. The differential reflects those market dynamics.

The trending future will steadily increase prices as the majority of new car sales in Europe are still in diesel. Booming new car sales in India, China, Russia & Brazil include diesels.

JasonG 01-24-2012 11:01 PM

Quote:

Originally Posted by CigaR007 (Post 282098)
Oddly enough, diesel used to be cheaper than gasoline, at least where I live.

Same here, my truck misses the $0.99 diesel it was used to.

Quote:

Originally Posted by sendler (Post 282100)
That's a crazy,radical piston. domed with a cavity. Lots of extra surface area. But Mazda says it wastes less heat by keeping the flame contained in the cavity.

The VW TDI uses a similar reverse dome with a peak piston. It creates less "wall stick" and more evenly distributes the fuel.


The good thing about a lower CR is you can add more boost without excessive peak cylinder pressures.
Wonder what size nozzles they are using and when bigger ones will be available :)

euromodder 01-26-2012 12:53 PM

Quote:

Originally Posted by CigaR007 (Post 282098)
Oddly enough, diesel used to be cheaper than gasoline, at least where I live.

Only due to differences in taxes.

Diesel is slightly more expensive to refine, but in Europe most countries put less taxes on diesel as it is the transport sector's fuel.


All times are GMT -4. The time now is 12:53 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2021, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com