Octane...

[Kienai]

This is a real stupid question, but.. What octane gasoline does everyone put in their stock KA? Just kind of wondering... Cuz I read somewhere that its better to put higher octane gas in your KA, it gets better gas mileage.. I just put 87 in mine, I really don't see a point in putting higher octane in a non-turboed engine.

[240marcuSX]

not only turbo engines require higher octane.

i use 87, because it really doesnt make a difference on a stock ka outside of ones mind.

[yeap]

I always put 91 in my car.

[xyoufailmex]

You're actually going to end up losing gas mileage and horsepower if your car doesnt need higher octane gas... And octane doesnt have anything to do with turbo or not... it's compression levels... High compression engines have to have high octane gas as well. Not trying to be nit picky, just dont want somebody who doesnt know to misunderstand.

[guyaverage]

In my 93 hatch, 93 octane made a world of difference. It felt downright lethargic on 87. I switched back and forth too many times for it to be in my head. It definitely made a difference.

In my 93 convertible, I have switched back and forth several times and can feel no difference whatsoever, so 87 it is. Using anything higher than what is required to prevent detonation is a waste.

[ArticDragon192]

87 octane here and made 130 rwhp on a stock KA.

[base9se]

91 octane and up!

[TheOne]

87 should be good for the stock ka, maybe 89 would do better.but addin higher octane can loose hp because the fuel would take more time to ignite than lower octane, that is why turbo/high compression engines use higher octane.....so it isn't prone to ignite faster/easier because of higher temps/compression.

[SloMoe]

The ECU actually compensates for it. Our ECU's have 2 different fuel and timing maps for hi and low octane fuels. Ever wonder why the fuel door says "Premium fuel recommended for maximum performance" ? It's not just for looks

[xyoufailmex]

Well, its not like that on any other car, and it doesnt make sense how an ECU can change the properties of the engines makeup which would affect octane... Im gonna check on my fuel door when I get time, never noticed it if it does, and it doesnt make sense why it would.

[swannjay]

octane level is just a measurement of the fuel's ability to resist knock or pinging. some engines only require regular unleaded while others require premium. its best to do what the manufactuer recommends.

[SloMoe]

Well, its not like that on any other car, and it doesnt make sense how an ECU can change the properties of the engines makeup which would affect octane... Im gonna check on my fuel door when I get time, never noticed it if it does, and it doesnt make sense why it would.

Its not changing the engines makeup, its changing the fuel and timing maps to more agressive ones. If its running a high octane map and detects knock it switches to a low octane map. Higher octane fuel burns quicker, so the ECU advances timing to take advantage of it. Ive played around and re-programmed KA ECUs, and all the Nissan ECUs Ive come across have the eeprom programmed with a hi and low octane fuel and timing map.

[grip_racer]

Its not changing the engines makeup, its changing the fuel and timing maps to more agressive ones. If its running a high octane map and detects knock it switches to a low octane map. Higher octane fuel burns quicker, so the ECU advances timing to take advantage of it. Ive played around and re-programmed KA ECUs, and all the Nissan ECUs Ive come across have the eeprom programmed with a hi and low octane fuel and timing map.

actually, high octane fuel burns slower to prevent detonation.

i think there's more factors to how fast a fuel actually burns though. i read something about how some fuels were made specifically for high-rpm motors because they upped the burn rate with some other factor than octane.

or something. i didnt quite understand it comepletely.

any fuel engineers on this forum?

but do ka24de ecu's really have two maps?

[SloMoe]

actually, high octane fuel burns slower to prevent detonation.

Duh yea thats what I meat sorry long day at work.

but do ka24de ecu's really have two maps?

Yes they do, in fact most Nissan ECU including SR and CA ecus have a high and low octane map.

[4gotn1]

i know my ka24e runs alot better on 93, it has alot more power to pull to redline (7k). it dosent pull as hard with lower octane. i have also noticed it runs better on spefic brands, it loves amaco and unreformulated chevron. everthing else make it sluggish.

[CDE]

I would probrably use a higher octane if it wasn't for the price of it. Gas prices have SUCKED here and for 93 it's over 1.06 dollars for 1 litre.

[4gotn1]

im paying 2.09 per gallon here, but i think its justified. my car runs so much better on it

[SloMoe]

2.09 a gallon is nothing compaired to what hes paying. It's about 3.8 liters to 1 gallon, so thats about 4.03 a gallon!

[4gotn1]

did i read that right?

DAMN... ill shut up now

[scruffy63]

well you have to realize over in cali they pay more for everything but they also make more money. so that evens it out a bit.

[AelSic]

He was talking about Canada Scruffy. Would all of you quit being cheap bastards and just buy the premium. That is exactly what our engines are built for and I am going to have to go with sloemoe there is a big reason the MANUFACTURER would tell you to use higher octane fuel.

[4gotn1]

if you read my post i run 93 in my car...aka premium

[skatanic28]

premium for me too.

[xxdjstriderxx]

i run 91, every few tanks ill add in a bottle of fuel injector blah blah blah cleaner.

when im poor, ill use 89 but i try to stay away from that. =( my engine has 168k so i want to feed it good clean stuff.

[2s4x0]

My factory manual for my 1998 240sx says premium, and i also have switched so much i can really tell a difference, and for an extra 2 dollars a week, its worth piece of mind and it feels better.