What petrol to use?

[2Fast4vtec]

Hey, how do you know what petrol you are supposed to use for your car?
I have a Nissan 1.5L twin cam, carb engine and the compression ratio is 9.5...
Do I use 91 or 96?

[Dr-X]

You'll be fine on 91.

90% of cars in NZ should be run on 91, but something like 35% of people are using 96.

[2Fast4vtec]

Cheers, just used to buying 96 for my 20v.

[Mr Revhead]

should be fine on 91.... certainly the comp ratio is 91 style! but dont be suprised if yu gotta back off the timing a bit...

japan doesn thave 91 their lowest is 96.
ever notice how many jap imports rattle their socks off.....

[ROBODISCO_20v]

You'll get better milage & performance out of 96. If you do lots of similar driving like going to work everyday, zero your trip meter when you fill up with 91 and then do it again with 96 and see how much difference you get. You may want ot do it a few times to get an average. I've done this with 96 and 98 in my Levin and found Mobil 98 to give the best milage and performance. Out of the 96 Gull was the best.

[Dr-X]

Bullshit Robo. Give me one good factual reason he would get better mileage from 96.

[ROBODISCO_20v]

You'll be fine on 91.

90% of cars in NZ should be run on 91, but something like 35% of people are using 96.

Where did you get this info from? The vast majority of cars in NZ are jap imports and like mr revhead said the min they got in japan is 96 not 91. So they should be run on 96

Dr X, everytime you post here you say something stupid.

[Dr-X]

The vast majority, these days, of cars are NZ new. Guess what? They dont tune NZ new cars for Japan conditions. Guess what? Jap cars are built conservatively from the start, so can easily adapt to any fuel with little or no performance difference. Guess what? We use a neat little thing called a knock sensor that virtually eliminates pinging.

Do yourself a favour and read a book moron.

[2Fast4vtec]

Just found out I should use 96.
http://www.faqs.org/faqs/autos/gasoline ... ion-1.html

[Dr-X]

I'm sorry, but that table is crap. It's saying that even at 8:1 compression we shouldn't use 91? Simply untrue.

[ROBODISCO_20v]

Dr X you're a fcuking idiot

[Dr-X]

Dr X you're a fcuking idiot

oe noes!!

So in other words, you cant actually come up with a logical rebuttle for my arguements?

[2Fast4vtec]

$&#$%. If you can’t trust the internet for facts, who can you trust?

[Dr-X]

$�$%. If you can’t trust the internet for facts, who can you trust?

How 'bout Dr-X, I heard he's pretty on to it.

[vvega]

You'll be fine on 91.

90% of cars in NZ should be run on 91, but something like 35% of people are using 96.

Where did you get this info from? The vast majority of cars in NZ are jap imports and like mr revhead said the min they got in japan is 96 not 91. So they should be run on 96

Dr X, everytime you post here you say something stupid.

yeah well

fact is if you time your car to make the most of the 91 octane without the knock sensor pully massive timming yourll find that the milage differance is ... well nothing

peopel tend to think that chanign a important componant like fuel will have no effect
it is unture to a degree.......if you dont retune your car to take advantage of the new fuel

providing your car is tuned to accept the new fuel and not pull the timing then you will not lose mileage

v

[Dr-X]

.... Now consider the car in question is a carby, eg not computer managed. But then, it doesnt really appear Robo has any idea what he's talking about. 'Yeeeah broooo, 96 maaaan, meeeeaaan performance and sweeeet economy brooooo'

[fivebob]

The vast majority, these days, of cars are NZ new.

Define Vast majority? Typically NZ New cars make up about 25% of the first time registrations, hardly a majority and most definitely not vast

Guess what? We use a neat little thing called a knock sensor that virtually eliminates pinging.

Guess what, a knock sensor is only useful if the car is tuned for the appropriate fuel, otherwise it's just a recipe for a blown engine, because the engine is constantly going through the cycle of knock/retard/advance/knock... which is not good for piston life. Knock sensors are good for the occasional batch of low spec fuel, not for the constant running on fuel below what the engine was tuned for.

Do yourself a favour and read a book moron.

Same old Dr-X. I see you still haven't learned much about things automotive or, for that matter, manners. I'd guess that you were looking in the mirror when you wrote that comment

[Dr-X]

The vast majority, these days, of cars are NZ new.

Define Vast majority? Typically NZ New cars make up about 25% of the first time registrations, hardly a majority and most definitely not vast

Guess what? We use a neat little thing called a knock sensor that virtually eliminates pinging.

Guess what, a knock sensor is only useful if the car is tuned for the appropriate fuel, otherwise it's just a recipe for a blown engine, because the engine is constantly going through the cycle of knock/retard/advance/knock... which is not good for piston life

This is still incredibly uncommon, because cars these days are engineers to be incredibly versatile. There's this rediculas myth floating around that just because the car is made in Japan, it wont like anything below 96. Almost all cars out of Japan (and certainly the car in question) will happily run on 91 without pinging at all. They dont engineer these cars thinking "oooh, we'll design it so if you run on anything less than 96, it'll ping itself to death". Notice how a lot of people are still driving around their Levins on 91 gas, and have been for 10+ years with no problems?

The vast majority, these days, of cars are NZ new.

Define Vast majority? Typically NZ New cars make up about 25% of the first time registrations, hardly a majority and most definitely not vast

Going back how car? Japanese importing is becoming more and more uncommon, and I seriously doubt that these day, only 25% of cars are NZ new.

[Mr Revhead]

well i was gunna say a lot.. but vega and five bob beat me to it....

Guess what, a knock sensor is only useful if the car is tuned for the appropriate fuel, otherwise it's just a recipe for a blown engine, because the engine is constantly going through the cycle of knock/retard/advance/knock... which is not good for piston life. Knock sensors are good for the occasional batch of low spec fuel, not for the constant running on fuel below what the engine was tuned for.

another reason to tune the timing to suit the fuel is 20vs, the factory setting are 10deg, but they hit the knock sensor, so settign them to 8 stops them hitting the sensor, which knocks em back 4-6 deg i think.
makes for smoother running and longer life.

dr-x.... your a special kind ****

[Dr-X]

well i was gunna say a lot.. but vega and five bob beat me to it....

Guess what, a knock sensor is only useful if the car is tuned for the appropriate fuel, otherwise it's just a recipe for a blown engine, because the engine is constantly going through the cycle of knock/retard/advance/knock... which is not good for piston life. Knock sensors are good for the occasional batch of low spec fuel, not for the constant running on fuel below what the engine was tuned for.

another reason to tune the timing to suit the fuel is 20vs, the factory setting are 10deg, but they hit the knock sensor, so settign them to 8 stops them hitting the sensor, which knocks em back 4-6 deg i think.
makes for smoother running and longer life.

I'm not talking about 20V's here. I was convinced ages ago that 20V's should probably be run on 96. It was just a passing comment that there are 20V's running on 91 just fine.

I'm talking about 2Fast4vtec's car, and most other cars on the road.