87 and low octane gas

[nikitopo]

Originally Posted by alf

if this is a case and engine is protected by ECU against low octane fuels, that's awesome.

Your ECU is protected against low octane fuels, but I wouldn't do often long trips under these conditions.

[steve99]

Originally Posted by conehead

You don't need a tune. The ECU will pull timing to protect the engine. However, since the engine was actually built for premium, your mileage and performance will suffer. A tune can't fix that.

Originally Posted by alf

if this is a case and engine is protected by ECU against low octane fuels, that's awesome.

Originally Posted by nikitopo

Your ECU is protected against low octane fuels, but I wouldn't do often long trips under these conditions.

Guys it true the ecu has timng compensations tiggered by the amount of knock the knock sensors detect but these compensations have limits
This motor is 12.5:1 compression and it needs decient fuel.


The minium recomended octane rating is 91 AKI MON (usa) and 95 RON in the european\australian\asian standard. This is from subaru\toyota



For best performance you need to un 93 or above MON and 98 or above RON fuels




Ive got logs of the stock tunes from peole running on the lower rating fuels ie 91 and 95 and the ecu is getting towards it maxium amount of compensation ie the IAM Advance multiplier as arround 0.2 or 0.3 and it was still getting FLKC knock indications of close to 4 degrees.


The IAM will be 1 when on good fuels and its minium value is 0.


So with 87 in tank its not going to be pretty your just going to get heaps of knock and the ecu wont have any compensation left. And 87 is way below the minimum​ standard recomended by subaru\toyota.


Here is a log from a srock car running stock tune on 95 RON fuel ie the minuim recomended. This wasnt on track this was jist normal road driving



https://datazap.me/u/steve99/south-a...8&solo=2-13-28

[bcj]

If you're going that far off the map, you may lose your twin in a pothole.
I'd rent a Suzuki Jimney that can handle the circumstances and is designed to run on low octane fuel.
Maybe a Hilux if you need auxiliary security personnel.

[alf]

Originally Posted by bcj

If you're going that far off the map

This is the point of the trip, sorry cannot reveal details yet. Risk is factored in and I am fully aware I might eject in the middle of the trip.

[alf]

Originally Posted by humfrz

What countries do you plan on driving your car through .. ??

no car there for 1000-2000 miles. in fact the roads are limited too.

[alf]

Originally Posted by steve99

Guys it true the ecu has timng compensations tiggered by the amount of knock the knock sensors detect but these compensations have limits
This motor is 12.5:1 compression and it needs decient fuel.


The minium recomended octane rating is 91 AKI MON (usa) and 95 RON in the european\australian\asian standard. This is from subaru\toyota



For best performance you need to un 93 or above MON and 98 or above RON fuels




Ive got logs of the stock tunes from peole running on the lower rating fuels ie 91 and 95 and the ecu is getting towards it maxium amount of compensation ie the IAM Advance multiplier as arround 0.2 or 0.3 and it was still getting FLKC knock indications of close to 4 degrees.


The IAM will be 1 when on good fuels and its minium value is 0.


So with 87 in tank its not going to be pretty your just going to get heaps of knock and the ecu wont have any compensation left. And 87 is way below the minimum​ standard recomended by subaru\toyota.


Here is a log from a srock car running stock tune on 95 RON fuel ie the minuim recomended. This wasnt on track this was jist normal road driving



https://datazap.me/u/steve99/south-a...8&solo=2-13-28

Steve, thanks for more technical insight. This is why I asked for OFT map which would eliminate knocking. For that leg of the trip, power does not matter.

I wonder though, in case I will not be able to get a map, if driving style (never WOT, stay below 4k RPM) would help eliminate some of results of using low grade fuel.

[Tcoat]

Originally Posted by alf

I truly mean what I wrote. Cannot reveal details. Not yet.

[humfrz]

Originally Posted by alf

no car there for 1000-2000 miles. in fact the roads are limited too.

If there are no cars and few roads, why would anybody be selling gas of any kind??

I suggest you have one of these follow you, then it can give you ride back to civilization when your BRZ fails. Oh, don't forget to have this vehicle tow a gasoline trailer.


humfrz

[humfrz]

Originally Posted by alf

no car there for 1000-2000 miles. in fact the roads are limited too.

If your objective is to destroy your BRZ out in the bush, may I suggest an plan B.

Drive it to Ft Irwin, CA and drive it around for a few thousand miles. Arrange for the post POL to air drop a couple of 5 gallon Gerry cans of gasoline every now and then. Then when your BRZ gives up, call for a CH-47 (Chinook) to extract you and whatever is left of your machine.





humfrz

[alf]

Originally Posted by humfrz

If your objective is to destroy your BRZ out in the bush, may I suggest an plan B.

Drive it to Ft Irwin, CA and drive it around for a few thousand miles. Arrange for the post POL to air drop a couple of 5 gallon Gerry cans of gasoline every now and then. Then when your BRZ gives up, call for a CH-47 (Chinook) to extract you and whatever is left of your machine.





humfrz

A little correction. While the area I will be traveling thru is super sparse, the longest segment of road with no gas stations is 666km long. I troll you not.

By 1000-2000k miles I meant no 91 or better gas. Ppl still live there.

[alf]

Originally Posted by humfrz

If your objective is to destroy your BRZ out in the bush, may I suggest an plan B.

If Fiat Panda made it (again it is not a troll), I should be able too. And I do have an advantage being 2 wheel driven (as opposed to 1 wheel for the most of cars). Odds that I will get suck are lower than getting TB in first 50k (s)miles.Which I replace as a preventive maintenance before the trip.

[x808drifter]

The more I hear, the more it feels like a Top Gear Challenge.

[Mr.ac]

Sounds like your better off buying a small tow trailer or extended hitch and a few jerry cans of your preferred gas.

By the way you sound, are you Canadian eh?

[humfrz]

Originally Posted by alf

A little correction. While the area I will be traveling thru is super sparse, the longest segment of road with no gas stations is 666km long. I troll you not.

By 1000-2000k miles I meant no 91 or better gas. Ppl still live there.

DANG, I reckon you plan on taking a few side trips -





humfrz