Mazda introduces clever start-stop system with direct injection
Mazda has announced a clever new start-stop system that promises fuel economy gains of 10% or more without the need for an electric motor. The Smart Idle Stop System (SISS) uses only direct injection and combustion to restart your vehicle, while most start-stop systems use an electric motor and traditional engine start-up process. SISS stops the pistons in the optimal position for an engine restart, and then injects fuel into the cylinders before the engine begins to rotate and lets the power of combustion turn the engine over to start. This enables an SISS-equipped Mazda petrol engine to restart in 0.35 seconds, or half the time of start-stop systems using an electric motor. The catch: SISS only works with automatic transmissions.
Mazda's SISS system will be available in 2009, but the Japanese automaker hasn't yet announced which models will receive the fuel-saving technology, nor has it disclosed whether SISS will be available in the States at launch. With Americans becoming increasingly sensitive to fuel economy and petrol prices, we hope we're not left out in the cold. Hit the jump to review Mazda's press release.
[Source: Mazda]
PRESS RELEASE
Mazda Motor Corporation has independently developed an idling stop system, called the Smart Idle Stop System (SISS), which improves fuel economy by about ten percent (in Japan's 10-15 mode tests*1) in urban areas where vehicles frequently stop at traffic lights or in heavy traffic during operation. The SISS uses direct injection technology to achieve an excellent engine restart, ensuring drivers do not experience any discomfort with the new system. Mazda plans to introduce this core environmental technology to the marketplace in 2009.
Idling stop systems save fuel by shutting down the engine automatically when the car is stationary, and restarts it when the driver resumes driving.
Conventional idling stop systems restart a vehicle's engine with an electric motor using exactly the same process as when the engine is started normally. Mazda's SISS, on the other hand, restarts the engine through combustion. Mazda's system initiates engine restart by injecting fuel directly into the cylinder while the engine is stopped, and igniting it to generate downward piston force.
In order to restart the engine by combustion, the pistons must be stopped at exactly the correct position to create the right balance of air volume in each cylinder. The Smart Idle Stop System provides precise control over the piston positions during engine shutdown to accomplish this. The SISS indexes each cylinder and initiates fuel injection before the engine begins to rotate. This enables the engine to be restarted in just 0.35 seconds*2, roughly half the time of a conventional electric motor idling stop system.
In addition to saving fuel, Mazda's Smart Idle Stop System ensures that the engine will restart quickly and with exactly the same timing every time. Drivers will feel no delay when resuming their drive, which means they can enjoy a comfortable and stress-free ride.
*1 The 10-15 mode test is the Japanese standard for emission certification and fuel economy for light duty vehicles. It consists of two separate drive cycles. The 10-mode drive cycle is a low speed drive cycle test, while the 15-mode is a higher speed assessment.
*2 For vehicles with automatic transmissions. Restart times measured by Mazda.
Reader Comments (Page 1 of 3)
No Welfare for GM 2:07PM (9/09/2008)
10% How about that.
I guess all those hacks who wanted CAFE to increase (for cleaner air, security, no wars) really were right, it's not all that difficult to make more efficient cars.
Reply
Tourian 2:13PM (9/09/2008)
Before we pop the champagne corks, lets find out how much the system will add to the typical car, and what impact it has on EPA ratings.
bob 2:15PM (9/09/2008)
10% plus no need for a start motor. That's a nice improvement, too.
As long as it works on DSG-style transmissions, this is good stuff and hopefully makes it to other brands.
MachinaDC5 2:23PM (9/09/2008)
Sometimes it takes a little push to get the ball rolling.
Fernando 2:38PM (9/09/2008)
I agree, it isn't that hard to think of ways to save gas. Think of all the tons of CO2 that will be saved each day in the LA rush hour commute when almost every car there shuts it engine off when not in use.
However, this doesn't say how well A/C would work in those situations. It's just not convenient to not have the A/C running on hot, smoggy days while sitting in traffic. Maybe they can incorporate an electric motor just to run the compressor.
TJ 4:46PM (9/09/2008)
wow. These pro-CAFE people are going to need socialized medicine when they dislocate their shoulders patting themselves on the back so hard.
Note: Increased government regulations are an impediment to private sector innovation, not an incentive.
naggs 5:03PM (9/09/2008)
this plus a dual clutch trans would be an unbeatable combo
it would be extremely nice if they could find a way to get this on manual trans
No Welfare for GM 6:33PM (9/09/2008)
TJ i agree, Is that why GM and Ford are begging government for money? Government is buracracy.......
TJ 9:54AM (9/10/2008)
No Welfare:
If you had the opportunity to receive a multi-million dollar low interest rate government backed loan for research and development, you as a business would not take it?
You would be in dereliction of your fiduciary responsibility to the stockholders NOT to take it.
And how, might I ask, does increased bureaucracy and regulation correlate to a low interest loan? It doesn't, so your post is retarded anyways.
216 2:17PM (9/09/2008)
I think that all cars in the future (2011 and up) should have some kind of Start/Stop Engine Technology in them, because it makes no sense to waste gas while sitting idle
Reply
mark v 2:18PM (9/09/2008)
Thats odd my golf cart at work, works the same way. It runs when you press the gas and stops when you stop. What a concept. Who the hell thinks of this crap. It took them that long to figure this can work on a car too.
Reply
Mehdi Cheddadi 2:28PM (9/09/2008)
It use an electric motor right? thought soo...
pe_tor 2:38PM (9/09/2008)
Why can't a system like this be implemented with a manual transmission?!
I know they worry about it working with what the driver is trying to do, and that is easier when the car is doing more of the thinking for the driver...
But if they just had it turn off the engine when the clutch is depressed and the transmission is in neutral for, say more than two seconds.
Then the driver could release the clutch and the car would stay off, but if the driver put the car back into gear, the engine would restart.
If the driver releases the clutch so the car remains off, then the trigger for restarting the engine could be re-depressing the clutch (wouldn't want going into gear without hitting the clutch to turn it on in that case of course).
I can't think of a contingency in that scheme where the driver could cause a problem by catching the system off guard and ending up with a car with it's gears engaged and it's engine off (hopefully that's not just because I'm not thinking of something obvious).
Of course, you still need electronic assist steering and brakes for something like that to work if the car is allowed to shut off while moving, but if they're doing that for the automatic cars already.
Reply
jjpg2000 2:51PM (9/09/2008)
That's how the Mini start-stop system works on the manual.
BigMcLargeHuge 3:04PM (9/09/2008)
I don't see why they couldn't be used in a DCG/SMG.
The operation is similar enough to an automatic. I realize its not stick-shift, but maybe a step in the right direction.
Bungle 4:20PM (9/09/2008)
Are we sure that this Mazda system doesn't work with manual transmissions? That's what the Autoblog author says, but one way to read the "*2" footnote in the press release is that 0.35 second measurement only applies to automatic transmissions, and maybe manual transmissions just take longer.
cheezwiz 6:14PM (9/09/2008)
Of course it can't work with a manual. The average driver in a manual only spends .25 seconds shifting. This thing would take too long to be tolerable - start, rev, then shift. That's like a full second added at each light. I'd scratch my eyes out...
While I'm only being somewhat facetious, I think it could be adapted to a manual - just make it turn on as part of the deliberate steps a typical manual driver takes (e.g. giving it some gas and starting to release the clutch) and place it at the stop position after the clutch is fully depressed. Then, make a clutch lockout for until the engine has started again.
raize221 2:39PM (9/09/2008)
Finally, an end to all that damn stop light creep when people with automatics repeatedly let off the brake pedal!
Reply
Kyledl 3:32PM (9/09/2008)
What about those people that stop at an intersection 2-3 car lengths behind the previous car? Then decide to move up after sitting there for a few minutes? All those people who have to let off their brake for one moron arent the cause of the problem, its the 1 moron who cant gauge distance properly.
benzaholic 2:45PM (9/09/2008)
Stop-start applications have been available off and on for decades in Europe. I think the early VW Rabbits in the 80s had it.
I can't figure out why it has never been available in the US.
I understand that the early versions resulted in no driven accessories while stopped, which would suck to lose air conditioning when you're stuck in traffic (which is when stop-start would kick in the most), but now they can just use the same techniques as hybrids have to use.
Another downside would be when the car gets old and has been somewhat neglected. It may not want to start in a third of a second when it's 10 or 15 years old.
Reply