Octane Requirement | Premium & Popular Delusions

SVT4ME · Jan 11, 2005

Kalos said:
They will not deviate advice from the Owner's manual, no matter what the truth is... You have to get at the truth from outside Ford...

Hmm... yes, that should go over quite well at the Ford dealer when you take it in for engine trouble. "I know Ford recommends 91 octane but I don't believe you, it's all a big corporate conspiracy, right down to the call-takers at SVT!"

zslaton · Jan 12, 2005

okay, let's settle this for Chaney. I am a friggin' engine engineer at Ford. I do not work for SVT, but I have worked on several engine programs both from a hardware and a software calibration standpoint. You won't feel the difference between 87-89-91 in one tank unless you run really aggressive setup with high CR and boost. But, over time the use of the non-recommended lower octante fuel will damage your engine. Ford doesn't recommend octane ratings based upon what some dope on the street thinks in terms of coolness of the engine based on octane rating, or as a part of conspiracy with the petrochemical industry. They recommend it because it is the most robust fuel given the myriad of things that affect engine performance and resistance to knock - CR, operating pressures, spark timing, etc. Trust me, Ford wants to provide you the best value, and they aren't going to recommend a fuel that you don't need.

Bottom line - you risk damage to your engine and voiding your warranty when you run a lower octane fuel than what is recommended in your engine. And your risk goes up greatly with each tank you put in your car.

My point is - DON'T BUY A CAR THAT YOU CAN'T AFFORD TO FUEL. If you are having trouble paying the extra 20 cents a gallon for premium, you probably shouldn't spend the extra cash for the SVT in the first place.

Now please lock this thread!

revamp · Jan 12, 2005

You know what just occurred to me? I hope Kalos intends on keeping his car until it blows up, because I certainly wouldn't want to be the poor sap who unknowingly buys it second hand from him...

WarMan · Jan 12, 2005

revamp said:
You know what just occurred to me? I hope Kalos intends on keeping his car until it blows up, because I certainly wouldn't want to be the poor sap who unknowingly buys it second hand from him...

That aint no lie. ^^^

bowersdaazian · Jan 12, 2005

Man, why wont any mods lock this stupid back and forth arguement thread! ive basically read the same things from page to page, IT NEVER ENDS!!!

WarMan · Jan 12, 2005

I think if we just ignore it, it'll go away. Lets do that. I am unsubscribing as of right now...

Kalos · Jan 12, 2005

Originally posted by zslaton Trust me, Ford wants to provide you the best value, and they aren't going to recommend a fuel that you don't need.

Trust Ford ? Like you did for SHO owners ? Wasting millions of their dollars on premium gas it turned out they didn't need ? It took SHO owner community research to find out Ford was lying to them - or more likely just didn't give a damn.

Bottom line - you risk damage to your engine and voiding your warranty when you run a lower octane fuel than what is recommended in your engine. And your risk goes up greatly with each tank you put in your car.

Bottom line is there there have been no excess failures reported from stock SVTs running 89 mid-grade. You know it is safe, the entire fuel chemistry community knows it is safe, and I know it too. (All bets are off for the 87 grade). Here's some quotes from experts who REALLY knows what they're talking about:

I personally use regular even though my owner's manual says you'll get better performance with premium" says Lewis Gibbs, consulting engineer and 45-year veteran at Chevron oil company. He's chairman of Technical Committee 7 on Fuels, part of the Society of Automotive Engineers (SAE) Fuels & Lubricants Council. Gibbs knows gas. "My wife runs midgrade (89 octane) in her car, and it's a turbocharged engine" meant for 91-octane premium, he says.

The only modern engines that should really need premium are those with superchargers, which force-feed fuel into the cylinders. "You're driving along and just tramp the gas and the knock sensor cannot sense the knock fast enough in some cases," because the supercharger boosts pressure so fast, says Bob Furey, chemist and fuels specialist at General Motors.

Are these experts idiots ?

SVT4ME · Jan 12, 2005

The Chevron guy, something tells me he and his wife probably don't drive cars in the same way that an enthusiast (the type of owner this site is aimed at) drives a car - in other words they're probably not even coming close to using the potential of the car's engine and might be able to get away with using lower-grade fuel.

The GM expert you quoted said "the only modern engines that should really need premium..." implying that in a perfect design world the only engines needing premium would be those with forced-induction. We do not live in a world where each car's engine is perfectly designed, there's still lots of room for improvement in gasoline engine design. That statement can't be interpreted as meaning that anything other than a supercharged engine can safely use lower-grade fuel.

Kalos · Jan 12, 2005

zslaton said:
okay, let's settle this for Chaney. I am a friggin' engine engineer at Ford. I do not work for SVT, but I have worked on several engine programs both from a hardware and a software calibration standpoint. You won't feel the difference between 87-89-91 in one tank unless you run really aggressive setup with high CR and boost. But, over time the use of the non-recommended lower octante fuel will damage your engine...Bottom line - you risk damage to your engine and voiding your warranty when you run a lower octane fuel than what is recommended in your engine. And your risk goes up greatly with each tank you put in your car.

Just curious: What is it about Ford engines which accumulates damage from one tankful of 89 gas to another. I assume - like a GM ECU - a Ford ECU suppresses detonation - if necessary (its probably not necessary) just to the point of complete combustion, so there should be no residue higher than with 91, and not too much stress. What exactly about the engine deteriorates on 89 and goes BOOM - that doesn't deteriorate on 91 ?

Incidentally, you don't write like an engineer. What Engineering school did you go to ? Do you have a BSME/MSME ? Are you a licensed PE in Michigan ? Just curious. You brought up your R&D "qualifications" - not me. Just wondering how much credibility you have compared to the GM and Chevron real experts quoted above.

jboylan · Jan 12, 2005

Here's another money saving tip for all you SVT drivers:

Instead of wasting money on expensive store bought motor oil, just by crude oil by the barrel. It works just as well, and you'll save a fortune.

Also, instead of buying new tires whenever you get a bad puncture or flat, just use some clear silicone.

Kalos · Jan 12, 2005

Originally posted by SVT4ME The Chevron guy, something tells me he and his wife probably don't drive cars in the same way that an enthusiast (the type of owner this site is aimed at) drives a car - in other words they're probably not even coming close to using the potential of the car's engine and might be able to get away with using lower-grade fuel.

You're probably right they don't floor the gas pedal at each stop light. But, it shocks a lot of people how little of their engine's potential they ever use - eg at highway speeds maybe only 20hp. Probably only a few dangerous idiots on this forum stoplight racing ever really use the full power potential of their engines requiring 91 premium. The biggest stress by the way is full charge, low rpm. At high rpm, octane requirement is actually reduced. The SVT engine produces most power at high rpm - which is another reason I'm deeply suspicious of claims an ordinary stock SVT, driven non-maniacally, will explode some day on 89 gas - or even accumulate damage tankful by tankful.

On the other hand, this Chevron guy may be a real risk-taker - allowing his wife to drive a turbocharged car with mid-grade gas. Hasn't he been warned the engine will disintegrate ?

The GM expert you quoted said "the only modern engines that should really need premium..." implying that in a perfect design world the only engines needing premium would be those with forced-induction. We do not live in a world where each car's engine is perfectly designed, there's still lots of room for improvement in gasoline engine design. That statement can't be interpreted as meaning that anything other than a supercharged engine can safely use lower-grade fuel.

The SVT has "only" 10.2:1 compression ratio, and the valve and compression chamber design is very modern. So, the reasons why high performance engines in the old days absolutely needed premium gas are just not there. (I understand GM's new Corvette engine has 12:1 CR and almost certainly needs 91 gas just to stay in one piece). That's another reason I think there is margin in the SVT design and 89 is very safe. Yes, with 91 - under certain worst case conditions - the SVT engine will produce slightly more horsepower, but for most of us non-maniac SVT drivers, this power will never be used, and in my view there's no sense in wasting money on gas whose potential is never tapped. We non-maniac SVT drivers are hostage to horsepower claims designed to attract street racers who have a psychological need to compensate for their short dicks...

jboylan · Jan 12, 2005

That makes no sense. I'm going to compensate for my short dick with a $20,000 tuned economy car? I don't go around bars dangling my SVTOA keychain in the air waiting for the women to line up.

SVT4ME · Jan 12, 2005

^^ Really?? I do! [rofl] [joke]

jboylan · Jan 12, 2005

I'm not saying I haven't tried, I just don't do it anymore. But seriously, that crude oil really works, you guys should try it some time. I have an article from some NASA engineers back in 1991 about how it will work really well in your SVT. I almost forgot to mention that it only works in the 2003 and 2004 models. Sorry 2002 guys.

Kalos · Jan 12, 2005

zslaton said:
okay, let's settle this for Chaney. I am a friggin' engine engineer at Ford. You won't feel the difference between 87-89-91 in one tank unless you run really aggressive setup with high CR and boost. But, over time the use of the non-recommended lower octante fuel will damage your engine....Bottom line - you risk damage to your engine and voiding your warranty when you run a lower octane fuel than what is recommended in your engine. And your risk goes up greatly with each tank you put in your car.

[hihi] [clap] [rofl]

Here's a statement from Ford (from http://shankmanbros.com/index.php?option=content&task=view&id=8&Itemid=. I added Bolding.):

Ford now has just "a handful" of cars that use premium, spokeswoman Sandra Badgett said. But those cars can use regular with no ill effects, she said.
"We generally recommended certain octane because that's where the engine is tuned to run the best," Badgett said. "If you put regular in a vehicle that wants premium, it's not going to hurt it. It's not going to drop dead on the road."

Well, that just about does it. Ford has spoken (the real Ford). The premium-only gasoline bigots are wrong. Mid-grade 89 is safe and there is no performance loss. Even regular 87 is safe in an SVT (though probably with very slight, non-noticeable performance loss). If they have no more stupid alarmist declarations about engines blowing up on 89, we can let this issue rest...

SVT4ME · Jan 12, 2005

And this statement from Ford came from where?

zslaton · Jan 13, 2005

Kalos, I have a BSME from Carngie Mellon, along with a BS in Public Policy from there. I have an MSME from Purdue with a concentration in combustion and thermal fluids. I also have 4 years experience working on and designing engines from a combustion standpoint, including controls and calibration and specifically working on some knock sensor calibration. There is a reason both CARB and the company want us monitoring it, and it isn't just to annoy you - although it is coming in a close second.

Yes, you have protections in the case of knock sensors and an ECU that can change spark timing if it senses knock. They're there, they work ok, but they aren't perfect. The other item to note is that while the ECU can try and compensate for knock, it can't always counteract it. Add to that the fact that everything else in the SVT - when the ECU switches it's dual length runners, the CR, the valve timing, etc. - has all been timed to assume the use of premium fuel and the combustion event that goes along with it. You may be damaging your engine, throwing off your emissions, cutting into your performance, etc. It's stupid... don't do it.

Look, it goes back to my original point. Don't buy a car unless you plan on following the manufacturer's recommendations. You know what they were ahead of time, and they are there for a good reason. I'll take the engineering community's assessment over some random spokesperson anyday. I happened to talk to numerous colleagues from numerous engine programs about your post today, and they all said your are misinformed and they would never do what you suggest. They suggested that I tell you that you should change your oil every 20,000 miles using Motorcraft parts and oil, since I am sure that someone somwhere has done it once and been fine. Or run on your OEM tires for 100,000 miles, since I am sure that someone somewhere has done it and says it is okay.

And I'm sorry that I don't sound like what you would expect an engineer to sound like... I don't know what that means, but I think I am more than qualified to speak on the subject.

microtonal · Jan 13, 2005

OT:
zslaton,

What's the horsepower of todays EEC compared to PC's ?

What kind of OS?
Open source?

Just curious...

robbob · Jan 13, 2005

Are these experts idiots ? [/B][/QUOTE]

That is debatable, but you are, without a doubt.

With every stroke of the keyboard, you are making yourself into a bigger and bigger fool. You are wrong. You've lost your argument many times over. Please just stop.

soffiler · Jan 13, 2005

zslaton said:
...And I'm sorry that I don't sound like what you would expect an engineer to sound like... I don't know what that means, but I think I am more than qualified to speak on the subject.

I think he meant you're too articulate. Engineers have a reputation for being weak in the grammar department. I know, I are one.

Nice job, by the way. I am a big believer in following the manufacturer's recommendations.

Octane Requirement | Premium & Popular Delusions

SVT4ME

zslaton

revamp

WarMan

bowersdaazian

WarMan

Kalos

SVT4ME

Kalos

jboylan

Kalos

jboylan

SVT4ME

jboylan

Kalos

SVT4ME

zslaton

microtonal

robbob

soffiler

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