DI vs Octane

[PWMDMD]

Originally Posted By: Zee09
I'd like to know if the combo of PI. And DI. Resolves the DI. Issues
or it it too early to tell? Very interesting topic.


I like that Toyota is starting to do PI and DI - theoretically not only the best of both worlds from a power/efficiency POV but also helps with DI's number one issue - carbon buildup - as it allows the detergents to come in contact with the intake valves - hopefully reducing carbon buildup.

That said I have yet to see any definitive evidence but it makes sense in my mind...

 

[Shannow]

There was an Audi patent too (back when Terry was on the board talking Audi stuff) that was pertaining to oil formulation to reduce GDI intake deposits.

 

[Ducked]

Originally Posted By: Shannow
https://www.sae.org/publications/technical-papers/content/2016-01-2252/preview/


"a high mileage 2008 Pontiac Solstice with over 800,000 km on the odometer" is a standardised test bed?

Not really, though I do see the problem.

A better (or complementary) approach might be to deliberately engineer blowby on a new engine, perhaps by modifying the rings. This could potentially give you more control and reproducability.

 

[jhellwig]

Originally Posted By: shanneba
87 octane gas may be less refined and have more impurities than 91.

https://www.sunocoracefuels.com/tech-article/octane-stability-high-octane-vs-low-octane-fuels

"87 octane fuels tend to be less refined and contain more unstable hydrocarbons.
As the months pass during storage these unstable components react to form gums, varnishes and lower octane hydrocarbons.
...
Even in proper storage 87 octane gas can start to degrade in 3 months, 93 octane fuel should last closer to 9 months before degradation is noticeable.
Keep in mind that 93 octane fuels are still susceptible to octane loss and vapor pressure decreases due to butane evaporation."


You can see the difference in BP premium verses regular. Premium is crystal clear and regular has an obvious tint to it.

 

[HondaBroMike]

Originally Posted By: Dylan1303
I thought premium had the most cleaning juice vs 87 at some stations. Shell comes to mind.

^ this. I just switched from Plus to Super or Supreme aka highest octane available in my market. (only like 92 I think)

 

[badtlc]

Originally Posted By: Speak2Mountain
I've read that higher octane may help w/fuel dilution in DI engines.


It helps with all modern high compression engines, not just DI.

 

[UG_Passat]

Originally Posted By: PWMDMD
Originally Posted By: Zee09
I'd like to know if the combo of PI. And DI. Resolves the DI. Issues
or it it too early to tell? Very interesting topic.


I like that Toyota is starting to do PI and DI - theoretically not only the best of both worlds from a power/efficiency POV but also helps with DI's number one issue - carbon buildup - as it allows the detergents to come in contact with the intake valves - hopefully reducing carbon buildup.

That said I have yet to see any definitive evidence but it makes sense in my mind...



Starting? Toyota has been doing D4-S for over 10 years now, originally being limited to Lexus models. None of the D4-S engines have IVD issues like their older DI only D4 motors.

 

[nap]

Some engines adjust their timing based on input from the knock sensors.