Regular or Supreme Gas? - Page 2

Brian Macgyver · 05-14-08, 01:09 AM

[quote=lowbanks;3309661]Even though I wear a size 9 shoe, I notice that when I put on a size 13, I run much faster.
I've googled this to death and can't find 1 article to support using higher octane on a well maintained engine if all that's called for is 87 octane.
The cost savings over years (and gallons) of gas purchases would buy you a new engine if you stick to regular.[/quote

Bingo!!
I was a mechanical tech for 20 years, and I agree.
The engine was designed to use the exact octane that is commonly available. Any higher octane level is wasted.
The engine was designed to use the available fuel. An overage of fuel octane capacity will only result in increased exhaust emissions from un-burned potential, resulting in added hyro-carbons released into the atmosphere, and reduced fuel mileage.
Additionally, an added level of wasted hydrocarbons will increase the heat and pressure on the catalitic converter, causing early failure of the catalist. The replacement of the "cat" is costly.
It is best to use the fuel recommended by the factory. The use of "premium" will cost you in the long run. Stay with the standard fuel mix!

Brian Macgyver · 05-14-08, 01:42 AM

Let's put this a different way.
I was asked to do this in racing off-road. Off-road racing uses cars on the longest sections of roads without any means of support.
In off-road endurance racing, you will run the longest on the lowest octane fuel that the car will run on without blowing up the engine. And so you design the engine to produce the most power out of the lowest possible grade of fuel. That is what the main auto manufacturers have worked for.
In newer technology, we have followed this model. We have reached a point where the increase of octane has no effect other than to increase wasted potential, I.E. hydrocarbons. When hydrocarbons are wasted, excessive heat is generated, causing harm to engines and other systems.

Brian894X4 · 05-14-08, 12:57 PM

So, everyone just wants to repeat the same old theory? Any comments on my post about how Toyota says that premium will produce more power and my comments as to why that probably is true?

By the way, why would anyone think that a race engine without things like knock sensors and in many casea any electronics at all, much less only needing to last one race or maybe one season, would be compariable to a mass produced automotive engine that needs to last (in Toyota's case) 200-300K miles and operate all over the world in various conditions using all types of petrol fuel?

gotmud · 05-14-08, 02:49 PM

FWIW, my '94 with 150K does seem to idle smoother and get enough of a mileage increase to offset the extra cost of a tank of premium. Plus, as alkaline747trio mentioned, you can advance your timing a bit and get a little more power.

Hilux · 05-14-08, 07:54 PM

Quote:

Originally Posted by gotmud

FWIW, my '94 with 150K does seem to idle smoother and get enough of a mileage increase to offset the extra cost of a tank of premium. Plus, as alkaline747trio mentioned, you can advance your timing a bit and get a little more power.

I'm too tired.

turbocruiser · 05-14-08, 08:08 PM

Lots of good information and bad mis-information going on here and it's all been beaten to death and resurrected and beaten again.

In any event I'll say that there is absolutely no question whatsoever that premium fuel is required for forced induction 1FZFE's. Not for the marketing, not for the additives (some of which work well actually), not for the extra economy (if there is any), not for the extra 'power' (if there is any) but simply for the delay in detonation. The thing about premium fuel for me at least is mostly over octane (although I admit I love Shell's premium additive package) and the amazing thing about octane (gross oversimplification offered here) is that the more you have in your fuel the less likely you are to pre-detonate within the combustion chamber. In a forced induction motor it is the difference between detonating on time and producing wonderful power or pre-detonating and grenading parts of the engine. In a normally aspirated motor it is the difference (sometimes) between all that pinging you hear, and all that pinging you don't. I guess for NA I'd just listen to the motor (literally); if it is pinging, well, go up a grade or two and see if it helps, and if it isn't pinging, don't. Pretty simple really so let's leave the poor horse lay now.

05-14-08, 12:57 PM	#33
Brian894X4 IH8MUD Addict Join Date: Feb 2004 Location: Oregon Posts: 636	So, everyone just wants to repeat the same old theory? Any comments on my post about how Toyota says that premium will produce more power and my comments as to why that probably is true? By the way, why would anyone think that a race engine without things like knock sensors and in many casea any electronics at all, much less only needing to last one race or maybe one season, would be compariable to a mass produced automotive engine that needs to last (in Toyota's case) 200-300K miles and operate all over the world in various conditions using all types of petrol fuel? __________________ 1995 FZJ80, modified for regional expeditions. Click here for more... My main website: In Search of History Expeditions Foreign Toyota 4x4s Military Toyota 4x4s Last edited by Brian894X4; 05-14-08 at 02:24 PM.

05-14-08, 02:49 PM	#34
gotmud IH8MUD Regular Join Date: Jul 2007 Location: Rock Ridge TLCA# 18039 Posts: 432	FWIW, my '94 with 150K does seem to idle smoother and get enough of a mileage increase to offset the extra cost of a tank of premium. Plus, as alkaline747trio mentioned, you can advance your timing a bit and get a little more power. __________________ -OK gang, you know the rules, no humping, no licking, no sniffing hineys. 1994 FZJ80

05-14-08, 08:08 PM	#36
turbocruiser IH8MUD Lifer Join Date: Dec 2003 Posts: 2,948	Lots of good information and bad mis-information going on here and it's all been beaten to death and resurrected and beaten again. In any event I'll say that there is absolutely no question whatsoever that premium fuel is required for forced induction 1FZFE's. Not for the marketing, not for the additives (some of which work well actually), not for the extra economy (if there is any), not for the extra 'power' (if there is any) but simply for the delay in detonation. The thing about premium fuel for me at least is mostly over octane (although I admit I love Shell's premium additive package) and the amazing thing about octane (gross oversimplification offered here) is that the more you have in your fuel the less likely you are to pre-detonate within the combustion chamber. In a forced induction motor it is the difference between detonating on time and producing wonderful power or pre-detonating and grenading parts of the engine. In a normally aspirated motor it is the difference (sometimes) between all that pinging you hear, and all that pinging you don't. I guess for NA I'd just listen to the motor (literally); if it is pinging, well, go up a grade or two and see if it helps, and if it isn't pinging, don't. Pretty simple really so let's leave the poor horse lay now. __________________ 97 FZJ80, Locked & Loaded, Safari Turbo, Safari Intercooler, LandTank MAF, HKS Turbo Timer, 3" Ceramic Coated Exhaust, OME HD 2.5" Suspension, DBA Slotted Rotors, ARB Stuff, 33" Revos, Center Diff Switch, Slee Stuff: Roof Rack, Step Sliders, TC Skid Plate, SS Brake Lines, DC Drive Shafts. HG PM'd, My Rocky Mountain Mojo Mobile!

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05-14-08, 01:09 AM	#31
Brian Macgyver IH8MUD Addict Join Date: Aug 2005 Location: Prescott Valley, AZ Posts: 748	[quote=lowbanks;3309661]Even though I wear a size 9 shoe, I notice that when I put on a size 13, I run much faster. I've googled this to death and can't find 1 article to support using higher octane on a well maintained engine if all that's called for is 87 octane. The cost savings over years (and gallons) of gas purchases would buy you a new engine if you stick to regular.[/quote Bingo!! I was a mechanical tech for 20 years, and I agree. The engine was designed to use the exact octane that is commonly available. Any higher octane level is wasted. The engine was designed to use the available fuel. An overage of fuel octane capacity will only result in increased exhaust emissions from un-burned potential, resulting in added hyro-carbons released into the atmosphere, and reduced fuel mileage. Additionally, an added level of wasted hydrocarbons will increase the heat and pressure on the catalitic converter, causing early failure of the catalist. The replacement of the "cat" is costly. It is best to use the fuel recommended by the factory. The use of "premium" will cost you in the long run. Stay with the standard fuel mix!

05-14-08, 01:42 AM	#32
Brian Macgyver IH8MUD Addict Join Date: Aug 2005 Location: Prescott Valley, AZ Posts: 748	Let's put this a different way. I was asked to do this in racing off-road. Off-road racing uses cars on the longest sections of roads without any means of support. In off-road endurance racing, you will run the longest on the lowest octane fuel that the car will run on without blowing up the engine. And so you design the engine to produce the most power out of the lowest possible grade of fuel. That is what the main auto manufacturers have worked for. In newer technology, we have followed this model. We have reached a point where the increase of octane has no effect other than to increase wasted potential, I.E. hydrocarbons. When hydrocarbons are wasted, excessive heat is generated, causing harm to engines and other systems.