Car drives start-stop equipped MINI
Car magazine has test driven the new MINI Cooper 1.6 with BMW's start/stop technology and likes it a lot. The system on the manual transmission car requires you to put the car in neutral when you come to a stop in order for it to work, which does seem a bit funky to us -- we don't know anyone who puts their car in neutral every time they stop at a light. However, once you learn to do that, you'll get all the benefits of having left your engine running, and you'll increase your fuel economy by about 9%.
The system also only kicks in once the car is up to full operating temperature. If you wish to turn it off (and keep the engine running at all times) there's a button near the gear lever. The MINI also benefits from having an alternator that only charges the battery when necessary, and a light indicator telling the driver when to shift up.
Performance-wise, driven with ultimate economy, the MINI matched Prius CO2 emissions and got -- count 'em -- 74 mpg. Assuming Car uses the Imperial MPG metric, that converts to a still impressive 61 mpg in our U.S. cycle. The zippier Cooper S turned in 46 mpg, or 38 mpg in using the U.S. metric. Even accounting for a drop in real-world mileage, those are still impressive numbers. This is the system that BMW is going to introduce across its entire range, and so far, it's an auspicious beginning.
[Source: Car]












Reader Comments (Page 1 of 3)
DriftPunch 4:09PM (9/04/2007)
I've always been under the impression that most wear (especially bearing) happens upon startup. Do these (and others with similar systems) have a preoiler? How has this concern been addressed? Is it a non-event?
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voodoobru 7:06PM (9/04/2007)
yes and no. the wear and tear is from a cold start because the oil hasn't circulated yet and you are running metal on metal initially. once the parts are lubed so to speak starting and stopping is less detrimental.
there are two major disadvantages to cold starts
1.the oil is sitting in the oil pan and not on the engine parts
2.the cat is cold and isn't up to a good operating temp
Don 4:41PM (9/05/2007)
These concerns have been addressed through a special alternator/generator setup.
But I'm not sure about those mileage figures...the turbo setup drops the mileage from 61 mpg to 38 mpg?
SherbornSean 4:12PM (9/04/2007)
People see our energy dependency and contribution to global warming and they look for silver bullets -- easy fixes that will save the world in an instant.
But the reality is that the silver bullets are illusory. But steady improvements in engineering are real.
Start/stop is a good idea. So is advanced electronic valve control. And diesels, in some applications, like big trucks, and hybrids too. You add up 5% savings here and 5% savings there, and you start to make real headway.
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James 4:14PM (9/04/2007)
I put my car in neutral when I come to a stoplight...
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James II 5:51PM (9/04/2007)
you're not the only one.
Rob 6:36PM (9/04/2007)
I was listening to Click and Clack and they said manuals should be in neutral at a stop. They joked that you'll have one big leg if you're always holding in the clutch.
Colin 9:23PM (9/04/2007)
Not only that Rob, but if you're hit from behind and your foot is knocked off of the clutch, you won't stall forward into the car in front of you or the intersection... although this really only works if you're using the handbrake as well. But you should be doing that anyway if you're going in neutral.
Kumar 4:17PM (9/04/2007)
Hmm....I pop mine in neutral at lights, unless it's a shorty. Otherwise, you're just sitting there with two feet planted to the floor.
About the starting friction thing. It was my understanding that it was just when all the oil had drained down, so when the engine is warm, and the stoplights are at most a few minutes, you shouldn't have a problem. The other issue with that was with the alternator, but there have been big advances with beefing them up for this type of use.
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Scott Eaton 4:17PM (9/04/2007)
I assume the "most wear on startup" story is only regarding the cold startups -- when the engine hasn't been running recently. A warm startup (during start/stop use such as the Prius engine, and cars with cylinder-deactivation) should always be primed once the engine has been used; meaning, the time the engine sits while stopped at a stoplight is far too short for the engine liquids to settle back to "cold" status.
OH and FWIW, I usually use Neutral when idling at a light, etc. to spare my clutch. Never had a clutch problem in my life before. (Although now I'm on a Prius with CVT).
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James 4:19PM (9/04/2007)
Huh? You don't know many MT drivers that put their cars in neutral at a stoplight? I thought one of the cardinal sins of driving a manual is keeping it in gear and depressing the clutch at a prolonged stop?
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skeptic 4:36PM (9/04/2007)
so did I...I always put my car in neutral at a stop light....
Doc Lucas 11:15PM (9/04/2007)
Ditto here, always in neutral when stopping or stopped. I sold my last car with 117,000 miles on it, still with the factory clutch, and I bet the hell out that car.
Carlos 4:22PM (9/04/2007)
I'm always in neutral at a red light.
I understand it's not the best practice (being in gear lets you escape, or stalls you if you're rear-ended so you don't fly into traffic), but keeping my foot down is hard! I can barely reach, to be honest... it bugs me that clutch pedal travels are always longer than the other pedals'.
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Logik 9:02PM (9/04/2007)
"it bugs me that clutch pedal travels are always longer than the other pedals'."
You need a clutch stop.
h8rain 4:26PM (9/04/2007)
Slightly off topic, but this would never work in an RX-8 (where if you have a short trip you are supposed to rev the engine and cut it off at higher RPM, so the engine does not flood the next time you start it, IIRC.)
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John 4:29PM (9/04/2007)
Yeah I learned to use a manual transmission a bit late, but always put the car in neutral at a stop. A guy I work with did it with his XKE and didn't have clutch problems - replacing a clutch in that car is one of those engine out jobs - so I think he had a good idea.
Glad to hear the MINI beat up the Prius.
I also agree, there aren't silver bullets but more of one new idea leads to another and another...
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Benson Leung 4:45PM (9/04/2007)
Why are you glad the Mini beat the Prius? You're comparing a 5-door mid-size sedan to a small diesel that's a fraction of its size.
That being said, this is good progress. I wonder if the starter in this system got an upgrade. Plus, I wonder how the system works in the wintertime.
Idling in traffic, or at stoplights : Bad for everybody, diesels included.
darth 8:34PM (9/04/2007)
its good the mini beat the prius cause the prius is one of the most boring cars out there
Thr mini is a small fun to drive car and it is great that it gets the same mileage
Jonathon Ramsey 4:37PM (9/04/2007)
Fascinating. I've owned numerous MT's (I've never owned an automatic), some for 10+ years (Volvo 850, MK I Jetta, Ford Festiva, 86 Trooper, etc), I've never taken the car out of gear at lights and I've never had to replace a clutch. I've don't know anyone who puts the car in neutral at lights. Well, until today...
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