vassosorphanides

Has anyone tried any Octane Booster for Porsche Boxster S (Model 986, 3.2 lt, Year 2004)? Any positive results on the acceleration? Is it worth it? Will it give any damage to the engine?

Macster

If you are running the right grade of octane gasoline there's no need for any supplemental octane booster. If you are not the cheapest/best solution is to run the right grade of octane gasoline.

There are octane boosters. Some raise the octane only by "0.1" not '1' so you add some and the octane goes from "89" to "89.1" (maybe).

Other octane boosters are stronger. No direct experience but 2nd hand info is Boostane appears to be pretty potent. The trouble is the stuff is not cheap and you have to blend Boostane and gasoline every time you fill up. Bad enough decades ago when I had to blend 2-cycle oil and gasoline when I filled up my 2-stroke motorcycle's gas tank. No way I'd want to revert to having to do something like that with a modern car.

About all octane boosters that really deliver any increase in octane do so by additives that most if not all car makers advise against using. MMT is one. With Boostane what happens is the additive leaves an orange/red colored deposit on the spark plug tip and O2 sensors. Other surfaces exposed to direct contact with combustion gases probably also collect deposits. This probably includes the converters. There is the question then what effect this will have on engine performance and O2 sensor and converter performance going forward.

Best advice I can offer is buy the proper grade of octane gasoline. Buy from a busy station to ensure fresh gasoline.

Last but not least there can be some benefit to if available where you are running a tank or two of Chevron Supreme gasoline to get the benefit of the Techron that comes in the gasoline. (When I switched from Shell V-Power to Chevron Supreme my 2002 Boxster engine perked up some after not even a full tank of Chevron gasoline.) Or you can shortly before an oil/filter service add a bottle of Techron to the gas tank then fill up the gas tank and drive the tank level down to a quarter of a tank or so.

Brian in Tucson

I can't speak for other areas, but here in Tucson, our gas all comes from the same distribution center. There is only one in the area. Only difference between the cheap brands and the good stuff is the additive package and the price. Cheap brands aren't that much cheaper, either. Chevron is getting out of Tucson, so probably the best additive package is Shell. Autozone or O'reilly sells Techron additive in quart bottles. It's a product I really believe in--it really does clean injectors and seems to help with age related pinging. Also cleans and maintains the sender in the gas tank. My 96 Dodge Dakota V8 pinged a lot when I bought it. A couple of years of Chevron or gas with Techron quieted it down. Can't feel a lot of difference in power, but at 256k miles it runs like a top. Might as well run Arco or Costco. And add the Techron.

I have used 101 octane booster. Not worth a crap for octane boosting. But it does seem to help for cars with somewhat old, sour gas. Used it in my stepdad's Olds with a 3.8. He was a snowbird and didn't come one year. The 101 helped get it started when the gas quality wouldn't do it. Don't know how it worked, but it seemed to work for me. BTW, Stabil seems like it buys you only about a year of protection.

Wine.o

I'm usually working with jet and rocket fuels, but I'm a combustion engineer and have a little insight here. The amount of energy you get from a gallon of gas (the "heat of combustion" or "lower heating value") is the same for all octane ratings. Higher octane means ONLY that you can compress the gas/air mixture to higher pressures before it autoignites (pings / knocks). Higher octane fuels allow the designers of the engine to increase the compression ratio without the cylinder firing prematurely. So going to a higher octane rating can get the designer higher performance / mileage, but with the engine design fixed, going to a higher octane than is necessary gets you nothing but bigger gas expenses. Save your pennies.

I would agree though that while all gas starts from the same sources, if you're not using a brand that comes with detergents mixed in then it's a v/ good idea to add a bit of cleaner to your tank on occasion.
Hope that helps.

GVA-SFO

Thanks for accurate answer Wine.o
I think the question raise at Porsche users, as by design "our" cars would like to see 92 or 93 octane to be "happy".
It is true that since a good amount of years, the ECUs includes knock detectors and if "triggered", it would change performances (i.e.: reduce advance timing) to match the mix in use !
When you know that, it is quite natural that "we" could tend to increase octane of the mix, ..in order to never be in the "knock detection" case ..and have the power reduced by the ECU !

In my side, I do very often mix 100 and 91 in order to be above 93, ..and be sure my knock detector ..stays in vacations !
It would be great to be able to read the ECU in a way to know when the knock detector did enter in action. (I.e.: like the R1, R2 and etc.., at what engine hours the last knock detector acted last !)

We can also mention here, that the octane number can be find using different standards (i.e.: RON, MON, etc) or in the USA, at the pump the octane number is the average of RON and MON or: (RON+MON)/2 while in Europe in general, the octane is displayed as RON.
I think a RON of 95 would be a MON of 86, so, a 95 displayed in Europe would be a (95+86)/2 or, would displayed in USA as 90.5 (probably rounded to 91 !)

..my two octanes ! (more than 2 cents)

bcrdukes

Wine o. - Thanks for the insight!

You mentioned saving our pennies. Seeing as Porsches require premium fuel, which in North America is likely 91 octane, is it safe to say that owners should be using this in order to maximize the efficiencies of which the engine and ECU was designed for?

NuttyProfessor

On a similar subject, I was at a Porsche gathering recently and one of the well-known mechanics in the area recommended putting standard Seafoam in the gas. I've put it in my old trucks but never thought to put it in a modern performance car. He claimed that the Seafoam wouldn't harm a Porsche and that it would help to clean the injectors. Thoughts?

Macster

You should strive to use the proper grade of octane gasoline. Porsche says to use 93, and if available where you live/drive you should use it, but 91 even IIRC 90 is ok to use.

But there is a trade off.

The lower the grade of octane the more ignition timing will have to be retarded to avoid detonation. My info is Porsche "tunes" its engines to run right at the edge of detonation. This allows for the most ignition timing but avoids detonation. The engine is most efficient at this point.

If you use something less than 93, 91 or even 90, timing is retarded. This results in less efficient conversion of chemical energy of burning the gasoline to mechanical energy. But it avoids detonation. More of the chemical energy of burning the gasoline goes out the exhaust pipe as heat. (Retarded timing raises exhaust gas temperature.)

'course, for many of us, 91 is all there is, and at some higher elevation areas 90 is all there is.

But if you have a choice, 93 is preferred over 91, and 91 is preferred over 90. You should not run a lower octane grade of gasoline than what the owners manual calls for.

If you have the choices of 93, possibly 92, 91, and 90, you can experiment if you are so inclined. Fill up with 93 and drive the car as you normally drive it and note how the engine feels and carefully note the fuel mileage. Repeat with 92, 91 and 90. From then on use the gasoline that gives the engine the feeling you most prefer and which delivers the best fuel mileage.

I don't know prices in your area but you might find that while 93 is the "best" overall (as it should be, for that is what the engine is tuned to use) the price of 93 might result in 92 or even 91 being the most cost effective gasoline. While mileage might drop off some with 92 or 91 the lower price per gallon might tip the scales.

Frankly the time I tried 93 with my Turbo -- this after years of 91 -- I didn't care if 93 cost me a bit more the engine's reaction to the 93 octane gasoline was worth a slight increase in cost per mile. This assumes there would have been. I didn't bother to run any mileage tests as I was on vacation and passing through an area where 93 was available and I used it a tank or two then was back to having to fill up with 91.

Macster

Sea Foam? I'm a bit leery of any additive that is reported to work both as an oil additive and as a fuel additive. That has the characteristic of a snake oil.

My experience is with Techron either blended in the gasoline that I pump into the tank -- via a Chevron Supreme pump -- or that I have added to the fuel tank prior to filing the tank with gasoline.

From the engine's reaction to using gasoline treated with Techron, Techron works.

I have used it enough to know it works and in fact works by just running a tank or two of Chevron Supreme. I like this as Chevron gasoline is available from a number of stations where I live and drive and is priced competitively to other comparable brands of gasoline. Thus when I feel the engine needs a "cleansing" I can just fill up the tank with Chevron gasoline and let the Techron do its thing as I drive.

Have to point out that in some cases when I used Techron there was no reaction from the engine. Based on my experience I took this not as a sign Techron didn't work only that the engine didn't have a sufficient build up of deposits to remove. For example while my Boxster reacted quite remarkably to Techron my Turbo did not. I attribute the Turbo's lack of reaction to the fact it is a more precisely fueled engine (it uses wide band sensors to allow the DME to more precisely fuel the engine) and thus a cleaner running engine. There was also the differences in miles on the engines. The Boxster engine had nearly double the miles on it compared to the Turbo engine.

I have no desire to use any of my cars as a test platforms to try to find an alternative to Techron.

Wine.o

GVA-SFO

Thanks for the great posts above.
I think we can be more descriptive with “pushing” the car.
In my opinion, there is an easy way to measure the (important) word “pushing” :

What is your gas consumption ?

When you do track, if you ever take a look at “MPG”, I think you will get a better view of the word “pushing”.
For example, in my case, with a Boxster (a 2001, 3.2 “S”) that has an engine close to stock (except performance filter, large intake tube, large throttle box, and IPD plenum), my “MPG” on track is in the range of ..5 or 6 at the best !

So, taking this in account, I ALWAYS felt that with such engine, and running on performance mode, the 91 ((R+M)/2) octane would be “risky”, (or be in the mode of triggering the knocking sensor) and I always feed the car with 100 ((R+M)/2))
On open roads, I mostly run with a tank that is filled with a mix of 91 and 100, ..this just to be sure that the knocking sensor is staying out of action.

Now, it is true that I think, if your MPG is around 20, you should have no need at all to spend additional money to give a better food to your car !
..My two cents !

GVA-SFO

May be a very important note on this topic : when doing mix with high octane fuels, be (more than 100%) sure that the gasoline you use is UNLEADED !
If you would use gasoline with lead, this will kill your catalytic converters.

Sunoco has some stations that offer 100 octane in few specific spots, ..even in California. For example, "My" place is in Redwood City on Woodside road. They have two pumps offering UNLEADED 100 octane gas.

Macster

Actually the highest cylinder pressures are obtained during part throttle/high load conditions when the engine RPMs are rather low and the car speed is low. Under this conditions the throttle is open quite a bit and the air pressure in the intake rises to nearly atmospheric with the result this allows good air flow into the cylinders.

This set of conditions sees the cylinder filling most complete which results in a higher cylinder pressure. This is what can trigger the onset of detonation which can then have the DME dial back timing.

NuttyProfessor

I just noticed this comment here on rennlist. I have high respect for Charles Navarro of LN. See post #34

https://rennlist.com/forums/987-981-...l#post15227922

GVA-SFO

Thanks Macster, interesting.
Do you know if Durametrics read the ECU log (if this is kept ?) to know what was the last occurrence of timing adjustment i.e.: after knocking sensor trigger ?
(I could think that the ECU would record the last occurrence in relation with the engine time, i.e.: like the R1, R2, etc are recorded ?)