True, but a high-quality pair of running shoes made from durable leather or other materials, on the average, is going to last a lot longer than a pair of $7.95 sneakers from Wal-Mart.

 

 

I just turn the feature off. By repeated engine start/stop how much gas is saved vs. wear and tear of start motor?

 

I'm trying to say that if these stop/start systems suffered from premature wear, automakers wouldn't install them because they'd have to pay much more money to replace these parts under increased warranty claims.

 

Of course. They tested on bench simulating repeated use of the motor/gear but it is true even well made anything if used repeatedly wear out will occur sooner. As well start/stop feature annoys me. Same with my wife.
As soon as she starts her car first thing to do is turning off start/stop. She does not like it either.

 

 

And as I've explained in previous posts, with the "non-defeatable" GM system, there are ways to fool it in Manual and/or ultra-creep conditions.

 

My XT5 has the stop/start and it is annoying when you press the accelerator to start up again. It is unnoticeable when it does engage but leaving it is bothersome. As Marshall says you can defeat it by moving the gear selector to the manual mode which is just a quick flip down from the drive position.

What I think is a better mpg savings is the cylinder deactivation from V6 to V4. When driving I don't notice anything unless I look down to the info screen and a green V4 indicator comes on. I'm not sure what actually activates this feature or what the actual fuel savings is however.

As a side note to the original post, I would never buy a Chinese built Buick, GM should keep them there.

 

Cylinder deactivation works by closing off the intake and exhaust valves, and shutting down fuel flow to the deactivated cylinders. It is programmed to activate only when the engine is running on a light load and the vehicle does not foresee any immediate need for extra power, which is why it will not activate in stop-and-go city driving.

In stop-and-go driving, the automatic idle-stop system is likely to save more fuel. Cylinder deactivation saves more fuel in constant high-speed highway driving (when automatic idle-stop will not save any fuel).

 

Thanks for the follow up explanation. Are there any fuel savings stats available for these features?

 

Your mileage may vary... Fuel savings with these technologies depends on whom you ask.

For the automatic idle-stop system, Wikipedia, quoting Edmunds, says that for "non-electric vehicles fuel economy gains from this technology are typically in the range of 3-10 percent, potentially as high as 12 percent". (Source)

Natural Resources Canada says that "[idle stop-start] technology reduces fuel consumption during city driving by 4 to 10% or more, depending on the extent of technology used and specific driving conditions". (Source)

For cylinder deactivation, Natural Resources Canada says that "CDS can reduce fuel consumption by 4 to 10%". (Source)

Wikipedia says about variable displacement (cylinder deactivation): "In typical light-load driving the driver uses only around 30 percent of an engine’s maximum power", and that "fuel consumption can be reduced by 8 to 25 percent in highway conditions". (Source)