GM Reveals 2019 GMC Sierra

[FenwickHockey65]

Originally Posted by mlee

The 19's look awesome but e-assist (stop/start technology) is why I went ahead a purchased the last model year 2018 without this "feature".

eAssist isn't start/stop. eAssist is a mild hybrid system, start/stop just stops the engine at red lights. And it's defeatable now.

[ilirg]

It's cool, but where the regular F150 is the ugliest truck on the market, it makes up for it with the Raptor looking pretty cool. This doesn't really distinguish itself enough to look like a bonified offroader.

[FenwickHockey65]

It's not a Raptor competitor. It's the Sierra equivalent to the Silverado Trail Boss, which is kinda a Ram Rebel competitor I guess.

[mlee]

Originally Posted by FenwickHockey65

eAssist isn't start/stop. eAssist is a mild hybrid system, start/stop just stops the engine at red lights. And it's defeatable now.

Hmmmm so this is something new in 2019 and different than e-assist. The 2018 I drove for a couple days had a stop line on the tach and charging display on mylink. Interested to see how this start/stop works, but doesn't sound like an improvement over e-assist. Just a different way to skin the cat.

[FenwickHockey65]

Originally Posted by mlee

Hmmmm so this is something new in 2019 and different than e-assist. The 2018 I drove for a couple days had a stop line on the tach and charging display on mylink. Interested to see how this start/stop works, but doesn't sound like an improvement over e-assist. Just a different way to skin the cat.

Not really. eAssist is a hybrid system that can produce power supplement the gasoline engine. Start/stop just provides enough auxiliary electricity to power the lights, radio, A/C, etc for a few minutes at stop lights.

[ilirg]

Originally Posted by FenwickHockey65

It's not a Raptor competitor. It's the Sierra equivalent to the Silverado Trail Boss, which is kinda a Ram Rebel competitor I guess.

Ahh ok, from the autoblog article they made it seem that way

[DGthe3]

Originally Posted by ilirg

Ahh ok, from the autoblog article they made it seem that way

I'm sure that to lots of people, any truck with any off-road enhancements is a deemed a Raptor competitor

[Martinjlm]

Originally Posted by FenwickHockey65

Not really. eAssist is a hybrid system that can produce power supplement the gasoline engine. Start/stop just provides enough auxiliary electricity to power the lights, radio, A/C, etc for a few minutes at stop lights.

Pretty much correct. e-Assist is a mild hybrid system that is capable of providing very moderate engine assist, particularly in launch situations. Stop-Start is simply that. It shuts the engine off when you come to a stop. Restarts it when you take your foot off the brake or depress the clutch pedal. The only thing I would say is different is the Stop-Start system doesn’t provide electricity to the auxiliary functions. That is all still done by your main electrical system. Similar to if you just turned your key (I know...what key?) to the Aux setting.

Combined with Dynamic Fuel Management, e-Assist can allow the engine to operate longer in reduced cylinder modes because the motor-generator can add torque and horsepower and allow the engine to work a little less hard. It also helps smooth out the transitions when the engine is activating or deactivating cylinders. Bottom line, better fuel economy without having to reduce the engine displacement, so max power and torque are always lurking in there somewhere.

[DGthe3]

Originally Posted by mlee

Hmmmm so this is something new in 2019 and different than e-assist. The 2018 I drove for a couple days had a stop line on the tach and charging display on mylink. Interested to see how this start/stop works, but doesn't sound like an improvement over e-assist. Just a different way to skin the cat.

eAssist is another step between conventional internal combustion vehicle & pure EV

conventional -> start stop -> mild hybrid (eAssist) -> full/strong hybrid (Prius) -> plug in hybrid (Volt) -> EV

[Martinjlm]

Originally Posted by DGthe3

eAssist is another step between conventional internal combustion vehicle & pure EV

conventional -> start stop -> mild hybrid (eAssist) ->48V mild hybrid (Jeep Wrangler, Ram 1500) -> full/strong hybrid (Prius) -> plug in hybrid (Volt) -> EV

48V is a whole ‘nother ballgame. With enough e-motor and battery, it can be almost as effective as a full hybrid. Within the next couple years, ALL Mercedes I4 and I6 vehicles will be either 48V mild hybrids or plug-in hybrids.

The other place where 48V gets fun is in applications that also add an e-charger. Basically, a turbo that gets full boost at 0 rpm, because it is electrically driven. When paired with a conventional turbo it can completely eliminate turbo lag. The e-turbo comes on at launch, then when the engine is at the right rpm, the conventional turbo kicks in and the e-turbo drops out.

[mlee]

Originally Posted by FenwickHockey65

Not really. eAssist is a hybrid system that can produce power supplement the gasoline engine. Start/stop just provides enough auxiliary electricity to power the lights, radio, A/C, etc for a few minutes at stop lights.

I did watch the displays on e-assist where it shows power storage and whether you were storing power or using it. I've also driven a hybrid Malibu where the A/C actually shuts off if you stopped for too long. E-assist didn't do that but I'm thinking start/stop would. You mentioned it could be turned off. Is this a user interface or via tune?

[DGthe3]

Originally Posted by Martinjlm

48V is a whole ‘nother ballgame. With enough e-motor and battery, it can be almost as effective as a full hybrid. Within the next couple years, ALL Mercedes I4 and I6 vehicles will be either 48V mild hybrids or plug-in hybrids.

The other place where 48V gets fun is in applications that also add an e-charger. Basically, a turbo that gets full boost at 0 rpm, because it is electrically driven. When paired with a conventional turbo it can completely eliminate turbo lag. The e-turbo comes on at launch, then when the engine is at the right rpm, the conventional turbo kicks in and the e-turbo drops out.

Forgot about the 48's. Yeah, they fit between mild & full. In terms of components and general usage, they are quite similar to a mild. But with so much more power due to the higher voltage they get most of the performance of a full hybrid but at a lower cost. I expect a lot of vehicles will be adopting 48 volt hybrid systems over the next couple design cycles. Unless somebody finds a better mpg/$ technology over the next few years.

[FenwickHockey65]

Originally Posted by mlee

I did watch the displays on e-assist where it shows power storage and whether you were storing power or using it. I've also driven a hybrid Malibu where the A/C actually shuts off if you stopped for too long. E-assist didn't do that but I'm thinking start/stop would. You mentioned it could be turned off. Is this a user interface or via tune?

It's a toggle switch on the dash.

[mlee]

Originally Posted by FenwickHockey65

It's a toggle switch on the dash.

Good call on GM's part... hopefully that switch remembers the last setting too.

and I really did get an 18 with the thought of avoiding this stuff.