AAA tests show 5-7% city mileage gain with automatic engine stop-start

[oldtamiyaphile]

FWIW, I have a car with Stop/Start and if the A/C settings are above a certain threshhold (relative to ambient) the S/S won't cut the engine. Some other brands use electric A/C compressors instead.

[MetroMPG]

Originally Posted by Daox

We mainly don't have start/stop because the EPA testing doesn't reflect any benefit. During the testing, there is no sustained periods where the vehicle is stopped and idling (or not). Its just speed up/down.

Re-read the first post. :P

That's the myth they busted. They ran the cars on the EPA urban cycle and reported a 5-7% gain.

And I imagine that most cars with automatic climate control will override auto stop if the cabin temp goes out of range (either cold or hot).

[Daox]

Haha, my bad.

[Xist]

The EPA lied to us?!

[oil pan 4]

People over on that gas gasbuddy forum were I do a lot of recruiting say auto stop-start is "a stupid idea" and "wont save any fuel" and some how "the car will use more fuel by restarting it".

Lot of idiots out there.

Trust me auto stop-start is nothing new, cars sold in japan have had it since the 1990s.
Finely time we got to get a little 1990s technology in some of these new vehicles.

[cRiPpLe_rOoStEr]

Some folks might think it would have some delay on the throttle response when the engine is turned on again, but it doesn't happen at all. Otherwise it could be a good excuse to get the BAS-hybrid system more widespread...

[nemo]

Originally Posted by oil pan 4

People over on that gas gasbuddy forum were I do a lot of recruiting say auto stop-start is "a stupid idea" and "wont save any fuel" and some how "the car will use more fuel by restarting it".

Lot of idiots out there.

Trust me auto stop-start is nothing new, cars sold in japan have had it since the 1990s.
Finely time we got to get a little 1990s technology in some of these new vehicles.

It would be interesting to see the demographics. Wonder how it would break out by age. People who started driving before fuel injection and HEI might be a lot less accepting.

[Hersbird]

I think when they say there was is NO benefit with the Epa test, they mean 5-7% isn't ENOUGH to offset the cost of the batteries, programming, and starters. 5-7% gain is probably more then other tests have shown using the epa standard because as pointed out the epa test doesn't have much idle time.

I also question exactly how they did the test. Did they disable the start stop of those cars and then run them with and without? Even then the savings they quote are based on numbers none of those cars deliver, and numbers based on future CAFE standards no cars will deliver. Saying a car with start stop installed but disabled loosing 5% efficiency, is not really the same as if that car was built without the added weight and complexity of the start stop in the first place may show less of a penalty. So based getting 30-40 mpg and seeing more realistic 3-4% improvement you would only be saving $50/year which should never pay for the initial investment and repairs of the system. On a hybrid it makes more sense, the stuff is already there and also allows for automatic EOC and pulse and glide.

[user removed]

Mazda’s Efficiency Strategy to Include Stop/Start, Energy Regeneration, Diesel, and More - Car News - Car and Driver

Here is start-stop without the additional hardware.

regards
Mech

[nemo]

Originally Posted by Old Mechanic

Mazda’s Efficiency Strategy to Include Stop/Start, Energy Regeneration, Diesel, and More - Car News - Car and Driver

Here is start-stop without the additional hardware.

regards
Mech

Interesting strategy.