87 and low octane gas
 

Hi,


I am looking for an option for 87 or low octane fuels ECU map. I currently use OFT to upload maps.


The reason is not to save on money, but be able to travel long miles in places where only low octane / grade fuels are available.


Thanks in advance,
Andy

Buy some BOOSTane, 16oz bottle of premium would take 15 gallons of 87 to 94. Cost about $16 a can.

91 octane is available nationwide. Don't worry about it.

Even if it's cheap 91 octane it's still better than trying to run 87 octane.

Like said, that shouldn't be a worry here in the US of A.

Even if you are waaaay out in the boonies, they will have a "hi-test" pump. Now, waaaaay out there, if that hi-test pump is all rusted and there are spider webs on the handle, and a mud dobber nest in the nozzle, you may wish NOT to use that pump (hard telling how long THAT gas has been in that tank).

I would just pump a few gallons of regular to get you on down the road to the next station.


humfrz

Lots of back country in WA, OR, ID and CA.
There have been a few crossroad hamlets with only a tank on legs behind the post office.
Usually have to go find the person with the key or only open from 6am to 9am for the farmers.
Some motorcycles with small tanks would have a problem.

The twins mileage has let me avoid them with only a small bit of advance planning
by filling up in a town with more than one station. They've got premium.

Howdy,


thx for the octane booster suggestions.




This is is for the trip in countries where there is no high octane fuel available. I probably need to do like 4k (s)miles in such places. It is not to save a few $sss..

PS. I am not going to Mars. But it is quite remote destination,

Countries? Or counties?

Pretty sure Canada and Mexico have 91 octane too.

From personal experience I did the Baja 1000 road trip to Cabo then boat over to Mazatlán, to Durango then back up to El Paso, and back to California.

There was only two times where I had to fill up with 87 octane in the whole trip. Rest of the time it had 93 and 91.

Pretty sure our Canadian buddies/travelers can chime in too.

Just where do you plan to go? Pretty sure you can get answers from members in between your trip.

now it sounds like op is trying to save money and the traveling to other countries is just a ruse :iono:

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.

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

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

It's protected on the stock tune, but don't expect to be making any power.

If at altitude and on 87 and your IAM value in the ecu drops to near 0 you're gonna be putting a bit of an extra load on your motor and it's going to take quite a hp drop.

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

We have International folks that may be able to help you out.


humfrz

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

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.

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.

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

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.

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

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.


:burnrubber:


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.

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.

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

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?

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


:iono:


humfrz

I do not speak French. Actually, I am grew up in Europe ...

that whole journey will be one huge side trip

So, I'm interested in following your journey.

Where are you going to start from?


humfrz

Thank you. The whole thing already started in my head, and after consulting with people who did similar I am more inclined than ever.


The only item on the check list I am really worrying about is how to get around the low octane fuel for 1000-2000 miles (perhaps less - I still need to check it). In fact, I have to find out that next.

Back to OP, I will run a tank of 87 and log data with OFT. I kinda hope, that measured driving style could limit knocking ... Maybe naive thinking.


Andy

I could make up a tune for you will a lot less timing for runnig low octane fuel, but on 87 with a 12.5:1 compression you likely still going to get some knock but with a modded tune it will be less


Message me if your interested

Thx. When I get to the point I am 100% committed, I will reach out to you.

Here is a thought that might help a bit.

When I was traveling in Europe, while stationed in the Army, I could buy gas at the EES for $.23 per gallon. On the economy it was selling for $.67 per gallon. I was driving a VW bug. So, I borrowed two 20 liter poly-something containers, that my landlord used in his business to transport dry cleaning fluid. I positioned these containers in the front of my bug, hidden under an Army blanket. That about doubled the range of my car on relatively cheap gasoline, allowing me to make it to another military installation.

(please folks, no lectures on how dangerous that was - :()


So, Andy, where in your head, did you start off from?

(London or Cape Town?)



humfrz

OP, you gave your name on a public forum. Are you sure you wanted to reveal that detail yet? [emoji6]

Seriously, you allude to the lsd being helpful in avoiding getting stuck on this trip. How is that kind of terrain compatible with going easy on the car to try and avoid knock?

Not sure about the point of all the secrecy on the plans. I personally would throw my idea out there since there is bound to be somebody on here that has experience in the regions in question.
At this point it would appear that Alf could not have chosen a poorer vehicle to travel through the unknown even if he had tried to.

@alf If by "far off the map" you mean take your car places it shouldn't, I'd advise reconsider or change plans. I've taken my car off into the dirt briefly while visiting the canyons and the wear that I did to all my mounts/shocks/ etc wasn't worth it. Dragged the muffler through a bunch of ruts. It made it, but to what cost to my future driveability and my wallet to have to fix these things?

If you must.. maybe trim 5* of timing globally by subtracting it from your base ignition timing map and see what happens? you'd be better off with that than running tables set for good fuel.

@steve99 offered to build a 87 map for me. I will run tests here at home to see what driving style works and what does not.


If there is a certain window of RPM/throttle where it works, I will stick to it. Also, I will carry octane boosters.



yes, I must.