Tuning an engine for 98 Octane Fuel?!

[mulla]

Hi All,

Sorry if this is a silly sounding question. I know what higher octane fuel does as in preventing premature iginition in higher compression ratio engines.

I remember seeing people loosely referencing the ability to "tune" an engine that originally not requiring PULP to take advantage of the higher octane thus producing more power. I've tried going through some old threads here and google but I haven't found any details as to what this "tune" really boils down to?

Was hoping that someone here can shed some like as to if this "tune" really exists, what it involved?

Thanks heaps in advance as usual.

Edited April 28, 2009 by mulla

[Guest]

Hi All,

Sorry if this is a silly sounding question. I know what higher octane fuel does as in preventing premature iginition in higher compression ratio engines.

I remember seeing people loosely referencing the ability to "tune" an engine that originally not requiring PULP to take advantage of the higher octane thus producing more power. I've tried going through some old threads here and google but I haven't found any details as to what this "tune" really boils down to?

Was hoping that someone here can shed some like as to if this "tune" really exists, what it involved?

Thanks heaps in advance as usual.

if it is a N/A engine, advance the ***** out of the timing.

[mulla]

if it is a N/A engine, advance the ***** out of the timing.

Oooh, thanks for the swift response :)

Hm... where could I get something like that done? It's just my gen 5.5 V6 Camry so yer it's N/A. Would the dealer service place be able to do that when I get a service done? Doesn't "sound" too hard a thing to do. Sorry I'm a totally n00b when it comes to mods of anysort!

[Guest]

I am not sure if a dealer would really want to advance it past factory... but if you went to a mechanic and told them you wanted to run 98 octane and have the timing advanced a little im sure they could do it for you.

[mulla]

I am not sure if a dealer would really want to advance it past factory... but if you went to a mechanic and told them you wanted to run 98 octane and have the timing advanced a little im sure they could do it for you.

Ahhh.... Yer I figured as much. Very last question (s), could I just go to any mechanic to do it? Like I know there's guys that advertise as being exhaust / muffler specialist, would there be ones for engine tuning? Also do you know roughly how much I should expect to pay for such a change?

Thanks heaps once again. Keeps my brain ticking while at work ;)

[Guest]

Not a clue as to how much it would be... I have done a similar thing to my car and I just did it myself.

I would just have a chat with a normal old auto mechanic about it... I cant expect it would cost too much, its a simple job.

[lateralus]

for a gen 5.5 camry with a 1MZ-FE, you should NOT advance the timing unless you get knocking. apart from the fact that the 1mz's have a very sensitive knock sensor, modern engines have the ability to adapt to the fuel they are using and slightly adjust the timing electronically to suit the application still within specification of the engine. if you put 98ron fuel in your camry, the ECM will do the rest.

1mz-fe have a relatively high compression ratio anyway (10.5:1), so 98ron fuel will run just fine with a factory setup

Edited April 29, 2009 by lateralus

[Guest]

Well there you have it... with older engines, advancing the timing is usually what you would do... but i guess the 1MZ will adapt.

[Whip Cracker]

Just wondering....

The same would apply for the 3VZ right?

[Guest]

Just wondering....

The same would apply for the 3VZ right?

Not sure if the ECU can compensate... or not... any v6 experts about?

[mulla]

for a gen 5.5 camry with a 1MZ-FE, you should NOT advance the timing unless you get knocking. apart from the fact that the 1mz's have a very sensitive knock sensor, modern engines have the ability to adapt to the fuel they are using and slightly adjust the timing electronically to suit the application still within specification of the engine. if you put 98ron fuel in your camry, the ECM will do the rest.

1mz-fe have a relatively high compression ratio anyway (10.5:1), so 98ron fuel will run just fine with a factory setup

Ahhh ok... Just thought I'd do something to take full advantage of the extra 10c that I pay for 98RON. :P If the ECM will adjust accordingly I guess I'll leave it as it is then. Thanks for the info as usual!

[aslan]

for a gen 5.5 camry with a 1MZ-FE, you should NOT advance the timing unless you get knocking. apart from the fact that the 1mz's have a very sensitive knock sensor, modern engines have the ability to adapt to the fuel they are using and slightly adjust the timing electronically to suit the application still within specification of the engine. if you put 98ron fuel in your camry, the ECM will do the rest.

1mz-fe have a relatively high compression ratio anyway (10.5:1), so 98ron fuel will run just fine with a factory setup

Ahhh ok... Just thought I'd do something to take full advantage of the extra 10c that I pay for 98RON. :P If the ECM will adjust accordingly I guess I'll leave it as it is then. Thanks for the info as usual!

yes mate B)

[Whip Cracker]

So this comes down to the idiots that say "Oh, 98 octane makes no difference over 95 octane"...

So, the reason why V6s benefit from it, is because the timing's changed to compensate for the better fuel...

So, in saying that, the people who don't notice any difference, or people who SAY it doesn't make a difference either don't have an ECM that can't adjust accordingly or possibly a smaller engine that may not benefit from higher octane fuel in the first place?

[DJKOR]

I would still say that in most naturally aspirated engines, if they were originally made to run on 91 octane unleaded, switching to 95 octane premium would make some difference, but going even higher to 98 octane unleaded will make no difference when compared to 95. There is only so much more that the ECU can adjust itself for.

[David the Viking]

The higher octane fuels are better for your engine as the internal parts eg: valves, pistons will be cleaner as there are more cleaning agents in the fuel. Keeps your engine running better longer.

My gen4 V6 has only had 5-6 tanks of normal 91 octane since I bought it new in 2000. Absolutely clean inside the intake ports and the valves look like new.

The 1MZ ecu's do appear to be able to take advantage of the higher octane fuels, as you really notice the difference when it tries to retune for the lower octane, it is ping city!

[Guest]

all you guys with your fancy adaptive ECU's.... haha.

[lateralus]

So, in saying that, the people who don't notice any difference, or people who SAY it doesn't make a difference either don't have an ECM that can't adjust accordingly or possibly a smaller engine that may not benefit from higher octane fuel in the first place?

yes, but not necessarily smaller engines. higher octane fuels only 1-2-09-33-5454really make a difference in engine with higher compression ratios due to the preignition resistance of the fuel. the 1mz has a compression ratio of 10.5:1, so high octane fuel still burns efficiently. however as a comparison, the 3vz's won't react as well as the 1mz's due to having a compression ratio of 9.6:1. even if the timing is advanced by the ecm (not sure how well those ecm's work) in theory you might even get worse fuel economy on 98ron due to not being able to ignite all the fuel thats injected, mostly due to compression

take for example a lot of nissans, the manufacturer recommends using higher octane fuels even on a lot basic models, due to the naturally higher than normal compression ratios of their engines

i'm not saying its a waste of money to buy 98RON fuels for lower compression engines, it still has a lot of benefits with the detergents and other cleaning agents, but to buy it purely to get more power and torque from it is stupid imo. it depends upon the car, and how well the ecm allows the engine to adapt. if you run your 3vz on 98ron and it runs well, good for you:)

[mulla]

Hm... turns out to be a very informative thread :)

Seeing Lexus with the 1MZ do call for 95 Octane, it would probably suggest that the 1MZ could benifit from 95RON without mods? But I would imagine the Lexus would have a different ECU to the Camry?

[lateralus]

the lexus 1mz's have vvti, so yeah, they have a different ecm

[mulla]

the lexus 1mz's have vvti, so yeah, they have a different ecm

Do you mean VVTL-i? I thought our Camry has VVT-i as well? Seeing that's written all over the I4 Camry.

[Hiro]

the lexus 1mz's have vvti, so yeah, they have a different ecm

Do you mean VVTL-i? I thought our Camry has VVT-i as well? Seeing that's written all over the I4 Camry.

I think the early Camry 1MZs didn't get VVTi, but the Lexus ones did. The Camry 2AZ 4-cylinder engine did get VVTi though

Edited April 29, 2009 by Hiro Protagonist

[lateralus]

the lexus 1mz's have vvti, so yeah, they have a different ecm

Do you mean VVTL-i? I thought our Camry has VVT-i as well? Seeing that's written all over the I4 Camry.

I think the early Camry 1MZs didn't get VVTi, but the Lexus ones did. The Camry 2AZ 4-cylinder engine did get VVTi though

no australian camry v6's ever got the vvti 1mz's, only the 2az (with the exeception of the 2gr-fe in american camrys obviously)

the lexus es300 had the 3vz-fe up until october 1997 before replacing it with the non-vvti 1mz-fe. they powered the es up until october 2001, until they replaced it with the vvti 1mz-fe that put out 158kw over the standard 145kw. but they ceased production in 2005

[mulla]

no australian camry v6's ever got the vvti 1mz's, only the 2az (with the exeception of the 2gr-fe in american camrys obviously)

the lexus es300 had the 3vz-fe up until october 1997 before replacing it with the non-vvti 1mz-fe. they powered the es up until october 2001, until they replaced it with the vvti 1mz-fe that put out 158kw over the standard 145kw. but they ceased production in 2005

Ahh.... Always thought the V6 had it too. Learned something new today :)

Thanks heaps for everyone's input!

[Whip Cracker]

Interesting about the 3VZ and the 98 octane fuel...

Understood about the whole engine compression and efficient fuel consumption/burning...

But who's to say that a 9.6:1 compression can't burn 98 octane efficiently? Obviously it'd be better in the 1MZ...

My 3VZ just LOVES the stuff. Maybe because these engines just go well with it, or maybe because it burns better with it... dunno.

On plain start-stop traffic, I get around 550km to a tank... no main road driving... top speed of 70km/hr.

[STYLSH]

But Shan, you drive like a grandma :P hehehe

I'd be lucky to get 500 without the blower and extremely lucky to reach 400 with it if there were no highway driving!