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Your T-5 is a perfect example Leon. People say it won't hold up to the extra power and torque but yours has lasted fine, I assume you don't floor it everywhere and do burnouts at every stoplight though. However I have a friend with a 96 ford ranger that has a 302 from a 72 mustang. Its bored 30 over, cammed, gasket matched and such. I believe it makes similar power to your 350. anyway he also has a T-5 backing it but his blew it in like 8000 miles because of his driving. He went to shift into 3rd and as soon as he applied power the gear exploded, spun around in the trans, and jammed his wheels.

My point is just because people say something can be used (like 87 in the S/C) doesn't mean it should. It might work but it could also go horribly wrong.

Zeik75 wrote:Your T-5 is a perfect example Leon. People say it won't hold up to the extra power and torque but yours has lasted fine, I assume you don't floor it everywhere and do burnouts at every stoplight though. However I have a friend with a 96 ford ranger that has a 302 from a 72 mustang. Its bored 30 over, cammed, gasket matched and such. I believe it makes similar power to your 350. anyway he also has a T-5 backing it but his blew it in like 8000 miles because of his driving. He went to shift into 3rd and as soon as he applied power the gear exploded, spun around in the trans, and jammed his wheels.

My point is just because people say something can be used (like 87 in the S/C) doesn't mean it should. It might work but it could also go horribly wrong.

I guess you failed to see my point, in that if a car is driving decent, your likelihood of failure is either eliminated (as in my case) or greatly reduced.
I think the common misconception is that, if you have the power, it needs to be put to the test at every opportunity and run the risk of blowing something up.
I've matured beyond that stage of my life, where as in the past it was fun, but anymore I appreciate what I have and enjoy my cars without feeling the need to test parts to the point of destruction every single time I'm behind the wheel .

You see this stuff all the time in motorsports, where an engine, trans, or rear gear gets torn up, and it's not the lack of well engineered and built parts, its because the parts are being operated at or near their design limits under severe conditions, as you would expect in the case of competition. But for a street car to be operated in the same fashion, on the street, is just asking for trouble, and there is no real surprise when something does go wrong. We see this from time to time at the dealership, where someone either has had some aftermarket part installed, not meant for that application and can't seem to get it to run like it used to, or it has suffered some extreme abuse to the point of failure.

My guess, is that if anyone expects to drive on the street as if they were on a race track, then by all means, I think the car should have the best of the best of the best.
And for guys like me that can take care of the machine and drive within its limits, that should be OK to, as I still am getting what I need and want out of my cars without worrying about "what next is going to break".

Leon

I think this discussion has morphed and shifted. The original post was, to paraphrase, "My wife ran regular gas in her 97 SSEi for 10+ years and didn't have an issue. Why does this forum make it seem life or death to run premium?"

Leon, the best answer is, that we don't know what the guy behind the other screen is doing, how he drives his car, or what he wants to do to it. He might Drive Miss Daisy, he might try to re-enact The Fast and The Furious. We have to assume the latter, especially for the kid who googles "1997 SSEi need premium gas?", finds this thread and thinks to himself, oh cool I can just run regular gas, and blows his motor up, and comes back trying to get something out of this forum or its owners. You're a professional, and you understand that sometimes you need to CYA, as well as ensure that the advice that you give out is correct for as many situations as possible, like I said before. We know that running premium in a supercharged car is the best thing to do. Anything else is at the owner's own risk, and their results may vary greatly. Yours seemed to be good, others have been disastrous, with both driving styles I'm sure on both ends of the spectrum.

It comes down to how much risk you want to take. An easy driver using 87 octane in a stock SSEi can sometimes get 50, 100, or even 200,000 miles and beyond without using premium. You are a case in point of that, but that's anecdotal at best. But we've seen here for years that it can take only one instance of knock to chunk a piston. And it's not even about driving hard or abuse - if you have to merge or pass someone, or are driving in hilly terrain, you're going to be in boost.

I think another key point is that the older SSEi's won't have quite as good knock sensing systems, and thus the need for premium is even greater.

I'm sure that the L67 can handle 87 octane when not beaten, but if I ever get one it'll always see 91+. I remember in my friend's GTP in highschool, he always ran 87 and it sounded horrible when he beaned it. Sounded like the supercharger was crying lol.

Thanks for letting me share with you all, my experiences with our S/c 3800.
It may be an isolated one, but it does show, with the right care, it can be done.

I never had any intentions of convincing anyone to follow my example in any way.
I thought it was an interesting topic, and one I wanted to shed a little light on.

Granted, where we live there are no hills to climb and no heavy traffic to merge with, so we were happy with the longevity of our 97 SSEi, regardless of what fuel was burnt through it.
As the old saying goes, "Your results may vary"!

Leon

Even under moderate throttle, I can tell the difference between 91 and 93.

I use regular unleaded here in the UK, which is rated at 95 octane 'RON'. I understand we use a slightly different measurement of octane over here though, and that 95 octane in the UK is roughly equivalent to 90-91 octane in the US. It runs well on this fuel, and returns impressive economy.

Our premium fuel is Shell V-Power and equivalents, which are 98-102 octane. V-power seems like overkill IMO.

So, I'm a little puzzled about which fuel to use in the UK, but haven't been too worried as my car runs fine on 95 RON and I assumed the premium fuel requirement was only relevant in the US.

Just another technical point, although not directly part of the discussion topic, but you can't ignore it. Lets say you net 4mpg better by using premium (to get 28-30mpg).

The break even point for the $3.60 you save at the pump (premium is only $0.20 more per gallon at most stations) is at $1.05/gallon. Any higher, you spend more money on gas. (BEPs: 1mpg/$5.10reg, 2mpg/$2.60reg, 3mpg/$1.94reg)

It might have made sense back in 2001, gas was about $1.00/gal. But since 2004/2005 gas has been over $2-$3/gallon. So if you put 50k miles on it since 2005, you spent easily $764 extra in gas. That's almost $10 per tank you save by using premium.

Given the high risk of internal engine damage, and the additional cost/mile to do it, running 87 octane is completely pointless unless you remove the SC belt.

This is an interesting thread. Does anyone know of an L67 that blew up on regular? In fact how many of you know of any unmodified L67 that received regular maintenance that blew up even on premium? As an FYI I bought my '02 SEi new and it just turned 200,000 miles. I always use premium and I get about 25 on the highway. The engine still runs great, supercharger gives a great kick, and it has never been apart.

In recent memory, Andrew had a customer with a Park Avenue Ultra come back with a chunked piston. Some of his project cars have also suffered similar fates.

You can get away with it on a stock engine sure, but you're getting less power/mileage/efficiency than on premium. It's probably around the same per mile on either, so just fill up on premium. If a couple bucks per fillup is too much for a budget, then you should probably revisit your budget.

00Beast wrote:

haro1225 wrote:When people ask me why I put premium in my car I tell them about this.
http://m.some other club.com/showthread.php?t=263718&page=5

http://tinyurl.com/n7enh6e

That's the link in a usable format.

Don't forget this car was running pretty hopped up, many tricks and tweaks to get the most out of the original equipment and get the PCM to run the engine the way he wanted it. This also shifts the "safety nets" built into the timing tables.

1tinindian wrote:

DaMaroon wrote:I'd be surprised if the retarded timing didn't cost some MPG so you weren't saving as much money as you thought. You paid extra for a car with a supercharger that basically didn't get used and you tried to save money by using cheaper gas that might destroy it. I fail to see any logic in this.

http://www.google.com/search?hl=en&site ... e&tbm=isch

I never once, said anything about saving money, and you have no idea what I paid for that car, so I fail to see your logic.
And in my area, it's common knowledge that the L67 never did get the MPGs that the L36 could get .
I'm only stating that we put a lot of miles on this car with no problem using 87 and thought it was unusual that people on this forum are so dead set on using premium fuel.

All any one here, so far, has said is that they "fear" possible damage, and not wanting to take the "chance" that something "might" happen using 87.
I'm just here to say, in our experience, that we had "no fear", we "took the chance", and got along just fine by not using premium.
Not saying it was the right OR wrong thing to do, just simply saying we never had a problem.

Leon

Sorry, didn't' realize you were posting from a parallel universe where the laws of physics and finance don't apply. You've given no proof that what you say is true and you'd have people believe that 100 years of engineering is a farce.
You're not saying it was the right OR wrong thing to do but I'm saying it is wrong. It's like saying "I ran with scissors maybe it won't put your eye out".

DaMaroon wrote:

1tinindian wrote:

DaMaroon wrote:I'd be surprised if the retarded timing didn't cost some MPG so you weren't saving as much money as you thought. You paid extra for a car with a supercharger that basically didn't get used and you tried to save money by using cheaper gas that might destroy it. I fail to see any logic in this.

http://www.google.com/search?hl=en&site ... e&tbm=isch

I never once, said anything about saving money, and you have no idea what I paid for that car, so I fail to see your logic.
And in my area, it's common knowledge that the L67 never did get the MPGs that the L36 could get .
I'm only stating that we put a lot of miles on this car with no problem using 87 and thought it was unusual that people on this forum are so dead set on using premium fuel.

All any one here, so far, has said is that they "fear" possible damage, and not wanting to take the "chance" that something "might" happen using 87.
I'm just here to say, in our experience, that we had "no fear", we "took the chance", and got along just fine by not using premium.
Not saying it was the right OR wrong thing to do, just simply saying we never had a problem.

Leon

Sorry, didn't' realize you were posting from a parallel universe where the laws of physics and finance don't apply. You've given no proof that what you say is true and you'd have people believe that 100 years of engineering is a farce.
You're not saying it was the right OR wrong thing to do but I'm saying it is wrong. It's like saying "I ran with scissors maybe it won't put your eye out".

There it is, the personal attack.
At the start of this thread, I had a feeling some one was going to go down that path.
You should feel proud of yourself for being that person!

What "proof" would be required? Are you calling me a liar, in that you don't believe we got over 170,000 out of our L67 on 87 octane? How do you propose I "prove" that?

Take the high road, and post like an adult, or refrain from commenting if you are that upset.
This is a discussion forum, keep the personal attacks out of it and lets open our minds to ALL thing out there, even if you don't agree with them.

Leon

170,000 miles - that's over $2300 extra you've spent in fuel.

Guess I should jump in on this, having spent years on these forums.

I can recall only a few failures specifically linked to preignition. Only one I can specifically recall is willwren's that was directly linked to a known low fuel octane. It's very rare that I have seen any engine go down from something other than a bottom end failure (bearings spinning, roasting, etc) or a valvetrain issue (breaking a valve spring and dropping a valve) in stock form.

So, to the question:

Will a stock L67 last a long time on 87 octane? Most likely. The more you are on the boost however, the more you increase your risk of changing this outcome.

What should you do? If you care about your car, you will run 91 or better. The very thought of a piston crashing in to a preignition grates on my nerves, and can't be good for anything. There are other benefits as well, such as confirmed improved economy. The best part? When the hammer goes down, the magic happens, and nothing stands in its way. The cost difference is worth the end result alone. It's $5 or so for a full tank. Once you run it, and the car adjusts, you will never go back.

What do I do? I am currently running 91 in my L27. Why? Because that is what it is happy with. 87 octane is met with knock and general irritability, same with 89 in the summer. A pissy car makes a pissy driver. Once it cools back down, I will likely back it down to 89.

So, in short, run 91 on boost, it just makes life easier, and is cheap insurance.

This thread =

1tinindian wrote:"Your results may vary"!

Leon

You forgot the most important part of the disclaimer:

Your results are not typical of what others have and will experience.

How about we don't have another thread derail and turn into a bunch of personal attacks...

agreed. Leon brought up an issue and there has been a lively discussion, the result of which is that we all learn more about our cars. Thanks Leon.