Last post on May 19, 2013 at 9:31 PM
You are in the Automotive News & Views
What is this discussion about?
Car Buying, Biodiesel, Diesel, Hybrid Cars, Coupe, Hatchback, SUV
#7937 of 9305 Re: Golf GTD [gagrice]
Feb 05, 2013 (8:15 am)
Mazda is basically importing everything now. The old 6 line is now Ford's.
Look at the Yen. Good bye profits.
Diesels have a higher margin and might literally save them.
#7938 of 9305 Re:SkyActive longevity potential [ateixeira]
Feb 05, 2013 (8:39 am)
I am still trying to understand how they have gotten fairly impressive output/fuel used in the gas jobs with their quite high CR's on 87 octane. I have read the measures they have taken to make it happen, but still seems a little out there. And further to their interesting approach, on the SkyActive diesels, how are they getting such impressively high torque and hp #'s yet still provide good FE and all the while do it with extra low CR's? Will this lower CR make the diesel a bit of a hard starter in extra cold temps?
I am also curious why no one else seems to be going after similar tech. SkyActive has been around for awhile now...enough time to generate at least some potential rumours of the competition to offer similar gas high compression, diesel low compression engines.
I know Mazda has always been the one to offer different type engine design. Their almost stubborn continuation with the rotary, and even the 2.3 that they used in the Mellenium...forget what was different about that one, but was a high output for a 2.3 and I don't think it was through the use of a turbo or blower was it?
So I also question engine longevity potential I guess, especially the high compression gas jobs on low octane. Even items like head gaskets...are they going to be a weak point once past 140000 miles sort of thing? Pistons..are they going to be prone to burn-thru due to pre-detonation from carbon build up in the combustion chamber raising the CR even further after miles well south of warranty has been racked up, thereby also being a head gasket life span stressor?
#7939 of 9305 Re:SkyActive longevity potential [gimmestdtranny]
Feb 05, 2013 (9:02 am)
Miller cycle supercharging effect and valve timing overlap. Neat oddball power trains. Just not successful perhaps because Mazda didn't have a consistent message.
SkyActiv-G and soon -D is similar I guess, but they have to get the tech in every model ASAP and then have a consistent marketing effort so people understand what it means.
140k would be fine (if that's what happens) as they'd be on the 3rd owner by then.
Great tech, look at real world mileage. It's the only hatch than can rival the Golf TDI in the real world. Even in the hands of Autoweek editors only the TDI and the Mazda3 could actually hit 40 mpg at 70 mph.
Can the SkyActiv-D hit 50 and knock the Prius out on Fuelly? It could....
#7940 of 9305 Re:SkyActive longevity potential [ateixeira]
Feb 05, 2013 (9:23 am)
Miller cycle....ya that's the one..
I did wonder what figure I should have used for my point..I chose 140k miles but maybe I should have said a very reasonable (low) 100k miles...cuz as we all know, for some owners, 100k goes by pretty fast. Maybe should have said 80 k, FTM..I don't know too many people that welcome a head gasket repair once at 100k. Part of the problem is not being sure you are getting a good job. More than a few head gasket (just as an example) replacements last the repaired warranty period but don't have a chance to compare to the original factory job's life potential. I did use a head gasket purposely though in this example because few other repairs are prone to improper replacement procedures that hide the bad job, slowly doing other life threatening damage to engine internals, and all the while often discovered out of wty and even if it is done under the repaired wty, the premature wear done to the engine internals are already done and owned by you as your liability. External leaks are the best to have if you get a botched job. It's the slow internal ones that concern me the most..
Repair quality, is one of my biggest concerns when it comes to a new car's longevity potential. The longer it can last through good design before a mechanic gets his/her hands on it, the better. Even if the repair is not horrendously expensive you still might get an excellent mech/job, but more often than not you don't...you only get fair or worse.. and this includes at the dealer too, not just indy efforts..
#7941 of 9305 Re:SkyActive longevity potential [gimmestdtranny]
Feb 05, 2013 (9:56 am)
I did use a head gasket purposely though in this example because few other repairs are prone to improper replacement procedures that hide the bad job
OEM headgasket failure is real as well. My 1973 Subaru blew a headgasket with less than 3000 miles. The Dealer in Anchorage was 9 weeks behind on repairs. They did sell me a new headgasket kit for around 100 bucks. I pulled the engine replaced the defective headgasket. Got it back on the road and less than a 1000 miles the other side blew. Same story booked up for months on warranty repairs. Bought another kit and replaced. No more headgasket failures as long as I owned the vehicle. I did not keep it a long time as it was lousy in deep snow.
#7942 of 9305 Re: Golf GTD [gagrice]
Feb 05, 2013 (12:17 pm)
I have two relatives that have the (2012's) Mazda 3's. I can definitely understand why folks like them. The 310 # ft of torque will put the higher cruise speed and mountain upgrade smiles all over those folks faces that get them AND the manual transmission. If Mazda gives their diesels the same "beefiness" (as their skyactiv gassers) I think they might have some unfortunate issues. The real issue is NOT just a few component parts. They are all connected. Some examples are beefier transmissions ( 310# ft but need to take a minimum of 350# ft (vs 148/168 # ft gasser) of torque, springs, shocks, struts as the TDI engines are normally heavier, H to V rated tires, bigger and stronger brake pads and rotors, etc.
#7943 of 9305 Re:SkyActive longevity potential [gimmestdtranny]
Feb 05, 2013 (3:38 pm)
I think the SkyActiv 2l is the base on the block in my Miata, and makes 145hp vs 170, and Miatas are grenade proof.
Then again the rotary burns oil and gets lousy mileage.
Let's see how their diesel does.
#7944 of 9305 Re:SkyActive longevity potential [ateixeira]
Feb 05, 2013 (4:12 pm)
You said "Then again the rotary burns oil and gets lousy mileage."
Lets be clear here.... a rotary engine is akin to a 2-stroke in that it is SUPPOSED to consume some oil. Mazda has done a masterful engineering job by minimizing the oil-consumption.
Likewise, BRP E-TEC 2-cycle engines (as seen in SkiDoo snowmobiles and Johnson/Evinrude outboards) consume virtually no oil. These engines may be the engineering marvel of the decade. The power and lightweight of a 2-stroke engine which meets many 4-cycle emissions.
It took NASA-designed metallurgy in thre pistons to achieve this high-point in engine-technology.
This also means NO OIL CHANGES!!! (because there is no oil in the crankcase)
The Downside: The E-TEC engines must be fed with very special 2-cycle injection oil.
If you want to learn more about modern engine technology.
#7945 of 9305 Re:SkyActive longevity potential [bpeebles]
Feb 05, 2013 (4:36 pm)
Fair enough, then.
I do trust Mazda powertrains.
#7946 of 9305 Re:SkyActive longevity potential [ateixeira]
Feb 05, 2013 (5:27 pm)
Have you ever been to a "street car day" at a dragstrip and saw the beating those Mazda's take?
Dont forget that this is AFTER the owner has added a turbocharger the size of a lawnmower-engine along with a nitrus. (I call that bottle-fed) From my observations, the 'weak link' is the CV-joints on the ends of the driveshafts.
The rotary-engines seem to be able to spin 15000 rpm because there are no reciprocating pistons nor valves to limit things.