In gasoline engines, Direct Injection 'GDI' injects the fuel directly into the cylinders under high pressure, where as MPI, TBI and other kinds of fuel delivery the fuel is injected or delivered into the intake manifold or intake manifold runners under low pressure.
+MikesCarInfo Pros and Cons of GDI. Higher pressures in general - GDI requires significantly higher fuel inlet pressures than port injection. This puts a great deal of strain on every piece of the fuel delivery chain. This is not a problem on a new engine. 50,000 miles down the road, and it may be. Manufacturers have been relatively proactive in this department by specifying robust, stainless steel fuel lines and connections. That hasn’t stopped fuel pump recalls from already occurring Carbon buildup on intake valves - This is the big problem with most current GDI engines. Due to modern unburned hydrocarbon (UHC) regulations, vapors from the crankcase are usually vented into the intake stream (PVC) in order to prevent oil droplets from escaping through the exhaust. In a port injection engine, these droplets are ‘washed off’ the neck of the intake valve by a relatively constant stream of gasoline droplets. In a GDI engine, the gasoline doesn’t touch intake side of the valve. As a result, the droplets have a tendency to bake onto the valve and significantly reduce performance. To add to this effect, many advanced GDI engines also include exhaust gas recirculation in order to lean out the combustion mixture and reduce in-cylinder temperatures for certain combustion modes (reducing NOx emissions). Since GDI combustion has the ability to produce far more soot than premixed combustion (port injection), the problem is magnified. Even more alarming is that these deposits can dislodge and damage other downstream components (turbochargers, catalytic converters, etc.). Manufacturers have added systems to capture these oil droplets and particulates, but no system is 100% effective. As a result, there are many disappointed early adopters with large repair bills. Even diesel engines haven’t been immune to these issues. The reason these issues have slipped through to production is that they won’t show up in a 500,000 mile torture test. These types of issues will appear after years of short trips (preventing the engine from reaching operating temperature), bad batches of fuel, etc. As we approach the efficiency limits of the internal combustion engine, the engines themselves (and associated support systems) have become more complex. As with the transition from carburetors to electronic fuel injection, there will be some overlap between relatively bombproof port injected engines and the unproven, first-generation GDI engines.
From what I was reading some manufacturers have introduced dual fuel injection. Direct injection downstream of the intake valve inside the combustion chamber and another smaller injector upstream of the intake valve, in the intake manifold, like multi-port injection. This way that smaller injector upstream of the intake valve washes the intake valve clean with gasoline. I think Ford, Toyota and some other manufacturers are starting to introduce this on some of their vehicles.
bigboi9870 I'm willing to bet you haven't physically walked over to a TV and changed a channel since the 90's. TV remotes make life easier and so does a push button ignition. Almost every new car the past few years whether it's luxury or non-premium has push button start. Ignition keys will soon be extinct in cars just like cassette players and 8 tracks. Get on board BigBoi.
Paul Chamberlin - you’re an idiot. I just bought a 2013 Denali and this interior is GORGEOUS and has everything you’d ever want to travel in luxury and comfort. Don’t compare a 2018 vehicle to a 2013 design.
Even the base model Acadias look upscale. 285 HP and yet a smooth ride!
You did a fantastic job COOL work
I know this is an old video...(new to me) but you forgot to talk about the HUD unit....
loved the video but didn't understood the explanation about the plus and minus symbols on the shift.
😊 thank you so much great job on explaining everything on this vehicle
In gasoline engines, Direct Injection 'GDI' injects the fuel directly into the cylinders under high pressure, where as MPI, TBI and other kinds of fuel delivery the fuel is injected or delivered into the intake manifold or intake manifold runners under low pressure.
+trucking604 Thanks for the info!
+MikesCarInfo Pros and Cons of GDI.
Higher pressures in general -
GDI requires significantly higher fuel inlet pressures than port
injection. This puts a great deal of strain on every piece of the fuel
delivery chain. This is not a problem on a new engine. 50,000 miles down
the road, and it may be. Manufacturers have been relatively proactive
in this department by specifying robust, stainless steel fuel lines and
connections. That hasn’t stopped fuel pump recalls from already
occurring
Carbon buildup on intake valves -
This is the big problem with most current GDI engines. Due to modern
unburned hydrocarbon (UHC) regulations, vapors from the crankcase are
usually vented into the intake stream (PVC) in order to prevent oil droplets
from escaping through the exhaust. In a port injection engine, these
droplets are ‘washed off’ the neck of the intake valve by a relatively
constant stream of gasoline droplets. In a GDI engine, the gasoline
doesn’t touch intake side of the valve. As a result, the droplets have a
tendency to bake onto the valve and significantly reduce performance.
To add to this effect, many advanced GDI engines also include exhaust
gas recirculation in order to lean out the combustion mixture and reduce
in-cylinder temperatures for certain combustion modes (reducing NOx
emissions). Since GDI combustion has the ability to produce far more
soot than premixed combustion (port injection), the problem is
magnified.
Even more alarming is that these deposits can dislodge and damage
other downstream components (turbochargers, catalytic converters, etc.).
Manufacturers have added systems to capture these oil droplets and
particulates, but no system is 100% effective. As a result, there are
many disappointed early adopters with large repair bills. Even diesel
engines haven’t been immune to these issues.
The reason these issues have slipped through to production is that
they won’t show up in a 500,000 mile torture test. These types of issues
will appear after years of short trips (preventing the engine from
reaching operating temperature), bad batches of fuel, etc. As we
approach the efficiency limits of the internal combustion engine, the
engines themselves (and associated support systems) have become more
complex. As with the transition from carburetors to electronic fuel
injection, there will be some overlap between relatively bombproof port
injected engines and the unproven, first-generation GDI engines.
@@trucking604 I've also read/watched people saying the oil smells like gas or is breaking down on some vehicles.
From what I was reading some manufacturers have introduced dual fuel injection. Direct injection downstream of the intake valve inside the combustion chamber and another smaller injector upstream of the intake valve, in the intake manifold, like multi-port injection. This way that smaller injector upstream of the intake valve washes the intake valve clean with gasoline. I think Ford, Toyota and some other manufacturers are starting to introduce this on some of their vehicles.
Here you go bro 👑
i have a 2014 acadia drives great but now i'm having problems with starting the vehicle now .What do you think is causing this.
The Acadia Denali is a nice looking SUV, buts it's starting to show its age. No push button start.....in 2015? What's that about?
J High Are you really that damn lazy that you have to have push button start, you can't just put a key in the ignition and turn it?
bigboi9870 I'm willing to bet you haven't physically walked over to a TV and changed a channel since the 90's. TV remotes make life easier and so does a push button ignition. Almost every new car the past few years whether it's luxury or non-premium has push button start. Ignition keys will soon be extinct in cars just like cassette players and 8 tracks. Get on board BigBoi.
J High i like the convenience of push button start my durango has it but i can live without it like on my acadia
J High and they are redesigning it soon as well
Condensation in the back light?
Jeep Fanboy 3692 Yes
Hi friend wath ist Aproximed price for this baby in usa i think import one to Costa Rica TNKS
Where can I find this vehicle 2015 Acadia same color interior and Pearl color on the outside around me I'm in the 46312 area East Chicago Indiana
Dash compartment, paperwork, kleenex, 38 special...
Whats Mpg?
shadownet2040 MPG stands for 'Miles Per Gallon'. How many miles the vehicle can drive per 1 gallon of gas.
How many miles does it get per Gallon?
shadownet2040 17 in the city and 24 on the highway.
Want one
👊👊👅👅
Mike how much are you asking for 2015 Denali white with tan interior
Arcadia
I don't sell cars.
Why is the steering wheel from like 2007, and the centre hub on the gauge cluster is also from like 2007?? The 2010 Terrain has more modern features 🙉
The only reason
19 mpg is not good gas mileage
It's a SUV......not a Prius
@@obijuankenobi6565 exactly.
Dated interior...
Paul Chamberlin - you’re an idiot. I just bought a 2013 Denali and this interior is GORGEOUS and has everything you’d ever want to travel in luxury and comfort.
Don’t compare a 2018 vehicle to a 2013 design.
These cars have tons of problems! DO NOT BUY! Gmc does not stand behind their products.
mine hasn't had a problem and we've had it for a few years now
My 14 Traverse has 98k miles, no problems
LETS WATCH UTUBE A Traverse is a Chevrolet, dude.
Alex Daley - you imbecile, they are based on the same chassis you moron. Same car, different styling.