The problems with GDI

[SC Maintenance]

31mpg on long interstate trips

I wonder if this is part of it? Theorizing? I think a lot of engines never get hot enough.

 

[Revving2Redline]

Which specifically - if you know or can share?

I use the Crc Gdi Intake Spray, Gumout Multitune 1 Oz per qt in oil and drive for 10 minutes to dealership for oil change, rest in fuel tank; it has pea in it as does the crc spray.

 

[Patman]

EFI should have been left alone, it worked fine.

It did work fine, however direct injection offers more power, better fuel economy and lower emissions, so those are pretty big things in it's favor for a manufacturer. The big negative is when it's prone to carbon buildup, but as it pertains to my car, from what I am gathering so far direct injection hasn't caused any serious problems since they introduced it on the Corvette in 2014. The C7s don't seem to have a problem with carbon buildup on the intake valves. I'm at 94,000 km on mine and it still gets great fuel economy and is still making great power.

 

[14.1 Grms]

I wonder if this is part of it? Theorizing? I think a lot of engines never get hot enough.

The 2.0L Ecoboost is actually efficient enough that, going down a hill with no throttle input at interstate speeds, coolant temp will drop at least 20-30 degrees. Highway miles tend to be very easy on it, even in 90-100mph traffic for 30-40 miles on end.

That said, half my daily commute is back/farm roads, and the engine is very well-revved through some sections.

My guess would be a lot of people, like one dude I work with who proudly proclaims it to everyone who will listen, is that they never take their car over 2500rpm for anything. That reduces stress on some components, but seems to cause more intake tract buildup (regardless of fuel injection type).

 

[dumkid]

VW even recommends an "Italian" tune up (15 to 20 minutes) at 3000 RPM (have to use a gear or 2 lower than the highest) to burn away deposits.

You would be surprised how often this works, especially on diesels with variable geometry turbos.

Cars need to be revved out once in a while, and on the diesels the turbo vanes can get stuck if you never make them move

 

[burbguy82]

Yes, thats the MPI + GDI. Its not just for that however. MPI is more efficient at idle and low RPM. It also allows them to size the GDI injectors better for load. I have a Toyota Dynamic Force 2.5l Rav4, and the gas mileage for a vehicle its size is very good IMHO - 29 overall mixed use city and highway, 35 ish on highway if I keep it under 75 - my calculations, not a computer.

did they get rid of that for the new model years?

 

[burbguy82]

240k on mine, 10k OCIs, no catch can, and I don't run top-tier fuel. Weird how I don't have any of the problems that anti-DI proponents constantly crow about. Weird. Idle is dead solid stable, oil analysis comes back great at 10k, doesn't burn oil, 31mpg on long interstate trips. It even has a horrible, terrible turbo to make things even worse.

I guess I must be the exception to the rule. According to the Youtube experts, my engine should be so full of carbon right now that it shouldn't even be able to physically turn over, let alone run.

you drive alot?, is the vehicle you are talking about the 6.7td?

 

[14.1 Grms]

you drive alot?, is the vehicle you are talking about the 6.7td?

A minimum of 100 miles a day (commute), but this is in the 2014 Fusion (2.0L turbo DI). The cinder block of a diesel only sees maybe 5,000 a year, if that.

 

[Just a civilian pilot]

I use the Crc Gdi Intake Spray, Gumout Multitune 1 Oz per qt in oil and drive for 10 minutes to dealership for oil change, rest in fuel tank; it has pea in it as does the crc spray.

How long have you been doing that please ( driving with 1 once Gumout Multi tune in the crankcase ) because I was thinking of trying that myself.

 

[burbguy82]

A minimum of 100 miles a day (commute), but this is in the 2014 Fusion (2.0L turbo DI). The cinder block of a diesel only sees maybe 5,000 a year, if that.

there is the answer on why you have no issue, you drive a lot, Italian tune up not needed for you, but for most they drive 10% of that.

 

[dumkid]

Cold engine+short trips is what kills most engines, that and no maintenance. Gdi just doesn't work good on a cold engine

 

[ejes]

did they get rid of that for the new model years?

No. It is one of the reasons I prefer Toyotas actually.

 

[Fabulous50s]

As you mentioned there were other improvements along the way. My bet is the numbers might be a little closer with those improvements minus the DI. The 3.6L Pentastar makes HP 305 HP in the RAM 1500 w/o DI. My bet is similar HP and mpg for your 2023 example.

That was the reason I bought a Pentastar.

 

[Doc8404]

The problems are lazy, broke vehicle owners who won't do the necessary maintenance and won't take unpopular steps to reduce the carbon / soot buildup.
Mid/premium fuel, 12k intake spray cleanings, shortened OCIs and Dexos 1 Gen 3 oils are just 4 of numerous, unpopular ways to help keep the engines cleaner.
Do a Google Search on this subject and find more ways. But if you just want to look at your GDI / TGDI outside in the backyard and continue to sit on your hands, then expect conditions to worsen over time.

Why or how does higher octane fuel help? We are doing top tier 87 in our new pathfinder

 

[SC Maintenance]

m

did they get rid of that for the new model years?

The dynamic force 2.5 (Rav4 and Camry) has had it since the new design. The 2.0 in the Corrolla Cross has it. I am unsure which other models have or are getting it - but there clearly moving this direction, not away from it.

 

[tiger862]

2012 Impala 180k and never cleaned valves. Still get excellent mileage for what my mom drives. Mom drives it hard. As a retired technician, cars need rpm.

 

[Revving2Redline]

How long have you been doing that please ( driving with 1 once Gumout Multi tune in the crankcase ) because I was thinking of trying that myself.

I don't go over 20 miles, all highway keeping rpm below 4k

 

[mrjlube]

I was nervouse about purchasing my 2021 escape with a GDI turbo 3 cylinder engine. It is my work vehicle delivering medicine for a major hospital in the area. I change oil every 5,000 miles....just recently changed to Amsoil XL and doing 8,000 mile oci. So far so good at 190,000 miles. Runs absolutely beautiful and hoping it continues....many miles of all freeway driving daily. So far been very happy except for my transmission going out at 100,000 miles.

 

[dumkid]

I was nervouse about purchasing my 2021 escape with a GDI turbo 3 cylinder engine. It is my work vehicle delivering medicine for a major hospital in the area. I change oil every 5,000 miles....just recently changed to Amsoil XL and doing 8,000 mile oci. So far so good at 190,000 miles. Runs absolutely beautiful and hoping it continues....many miles of all freeway driving daily. So far been very happy except for my transmission going out at 100,000 miles.

Don't those have an oil bath timing belt?

If the timing belt breaks tell us, because some people want to know if they're any good

 

[14.1 Grms]

Why or how does higher octane fuel help? We are doing top tier 87 in our new pathfinder

High octane fuel does nothing unless the compression ratio of the engine requires it. Running high octane in a low compression engine is actually ungood, since the fuel doesn't burn completely (octane being the resistance of fuel to compressive detonation) and leaves deposits behind. DI/TDI engines are normally high compression enough to need high octane, but not always.