2016 Honda Civic with 375,000 miles, 1.5T engine - Reddit link

[CharlieJ]

And not one post in that reddit thread arguing about the oil viscosity used to achieve the total miles on the car. Looks like the recommended viscosity for that engine is 0w-20, hmm...

 

[VTECOverRated]

DI engine with high miles isn’t worth analyzing because it “has had an easy life”. DI engine with low miles “hasn’t been driven enough to see the damage”

These guys are sure though, that DI engines and dillution ARE a problem, even though there’s zero evidence. Apparently it takes 200k miles of driving 5k miles a year for dilution to take its toll, for everyone planning to keep their cars for the next 4 decades

That is because you took all the nuance out of everyone's equations and simplified it into something that is unintelligible.
Fuel dilution will cause damage if the oil isn't changed regularly, or if it is changed at long intervals where fuel starts to exceed critical levels. The reason fuel dilution happens is due to fuel being injected at high pressures directly at cylinder walls of small turbo motors that run rich to maintain lower cylinder temperatures, thus not burning all said fuel, which gets scraped its way into the oil by the piston and/or gets pushed through as a result of blow by because of high cylinder pressure of TGDI engines.

The reason 100% highway mile TGDI engines aren't impressive, is that they are effectively, running on vacuum, with much lower cylinder pressure and running with as little fuel as possible, so if there was fuel dilution, it was probably a smaller amount, and this is aided by long highway trips where the engine oil reaches the 60C temperature it needs to separate the fuel and evaporate it back through the PCV system. This is why TGDI engines are not recomended for lots of short trips and cold weather, that the oil doesn't reach high enough temperatures to allow for the fuel to separate and evaporate. Also most people end up lugging the engine more in stop/go traffic in cities, increasing cylinder pressures over and over for no reason.

In the city, where you drive very short distances, over short periods of time, or sit in traffic idling at very low RPM, your engine oil simply doesn't warm up as fast. 30 minutes or more are required. See this video for actual testing and data:

 

[VTECOverRated]

And not one post in that reddit thread arguing about the oil viscosity used to achieve this mileage. Looks like the recommended viscosity for that engine is 0w-20, hmm...

I can attest to this. Both my 1.5t and 2.0t run 5w30, and if the climate is sub 60F, I average 3 or more mpg on average LESS until the engine warms up after my 30 minute commute to work. With 0w20 I get more than what is advertised. On my 2018 2.5 camry I run toyota's 0w16 (and have done so for 260k miles) and average really good gas mileage, I am pretty sure on 0w30 or 5w30 it would be worse.

 

[SavetheRimBrake]

Fuel dilution will cause damage if the oil isn't changed regularly, or if it is changed at long intervals

Those will damage an engine in the long run, regardless of fuel content in the oil

 

[CharlieJ]

I can attest to this. Both my 1.5t and 2.0t run 5w30, and if the climate is sub 60F, I average 3 or more mpg on average LESS until the engine warms up after my 30 minute commute to work. With 0w20 I get more than what is advertised. On my 2018 2.5 camry I run toyota's 0w16 (and have done so for 260k miles) and average really good gas mileage, I am pretty sure on 0w30 or 5w30 it would be worse.

I'm referring to the total miles on the vehicle, not the gas mileage. Sorry for the confusion!

 

[VTECOverRated]

I'm referring to the total miles on the vehicle, not the gas mileage. Sorry for the confusion!

Ah. Even then, I doubt that it very low load it would make a difference.
I mean, here are dyno charts from ktuner (which I run on all my turbo honda's), the dotted line is factory tune, and its making 40hp at 2000rpm if he is cruising on the highway, he is only putting down 120lbft of torque and that would only happen at WOT on a dyno, so probably even less, just enough to keep the car running.

EDIT:
Here is another thought, I wonder more about the condition of the CVT, which if he is cruising on the highway all the time, it is also experienceing far less wear. I have had nothing but issues with CVT's past the 100k mile mark if its not taken care of religiously, where it starts to noticeably slip up hill and the like. Again, my 2018 camry needed a new trans before it needed a new engine at 260k.......on 0w16 oil.....

 

[buster]

Here is yet another example of a guy doing 3-4k miles per month and getting 200k out of a ZR2. Short trips and severe service are terrible for engine logevity.

This guy used GM dexos brand oil following OLM.

 

[Triple_Se7en]

DI engine with high miles isn’t worth analyzing because it “has had an easy life”. DI engine with low miles “hasn’t been driven enough to see the damage”

These guys are sure though, that DI engines and dillution ARE a problem, even though there’s zero evidence. Apparently it takes 200k miles of driving 5k miles a year for dilution to take its toll, for everyone planning to keep their cars for the next 4 decades

In reference to this 1.5 engine and mostly city driving....
Thin oils + increasing fuel dilution take their toll sooner than thicker viscosities..
If you have a diluter / thin oil combo (0w8/16/20, change the oil at 3k
If you have a diluter / 5w30 combo, lots of evidence here at BITOG signals 5k OCIs are not engine threatening in the long run.

 

[SavetheRimBrake]

Thin oils + increasing fuel dilution take their toll sooner than thicker viscosities..

Yet there is no evidence of this except for UOAs that don’t show wear

 

[TiGeo]

Not permitted here.

 

[4WD]

Here is yet another example of a guy doing 3-4k miles per month and getting 200k out of a ZR2. Short trips and severe service are terrible for engine logevity.

This guy used GM dexos brand oil following OLM.

View attachment 170326

Removed the multimatic kit ?