Fuel these days... - 986 Forum - The Community for Porsche Boxster & Cayman Owners

tnoice · 10-03-2009, 05:07 AM

So yesterday, I went to my favorite gas station in Champaign and found that they had changed the formula of the gas provided to the gas station. They now had posted on every pump that their gas contained 10% ethanol AND a new STP additive. Maybe I am ignorant to the new ways, but can't we buy normal unihibited gas anymore. This stuff is dilluted crap..

I filled up with a similar gas a couple of weeks ago while I was in Chicago, with our FJ, and within 50 miles it sputtered and the gas milage dropped tremendously. Yesterday I filled up at another gas station, out of town a bit, without all the advertisements, and the fj was back to normal.

Is this what we must look forward to in the future, No gas, just additives!!

Simply had to vent, thanks.. :dance:

Brucelee · 10-03-2009, 05:32 AM

I hear you. Sometimes these formulas are change via compliance with emissions laws. In CA, the law mandates a switch in the summer.

Then, in winter, back again.

blue2000s · 10-03-2009, 06:34 AM

All gasoline has additives. Detergents, anti-gel and stabilizers. Without them gas doesn't last long and your engine becomes a big carbon block. The oxygenators aren't necessary but they're almost always there too.

Cloudsurfer · 10-03-2009, 08:14 AM

If you want "gasoline," try race fuels or avgas (unfortunately, avgas is highly leaded). The crap that they call "gas" that goes in your street car is highly diluted and filled with who knows what. Formulations differ from company to company, state to state, and season to season.

mptoledo · 10-03-2009, 07:36 PM

I try to use the following site(click on retailer) as a general idea what gas isn't crap, but in my small area I am lucky to find a Shell station and Chevron is out of the question.

http://www.toptiergas.com/index.html

edevlin · 10-03-2009, 10:09 PM

" but in my small area I am lucky to find a Shell station and Chevron is out of the question"

Me too, we only have a Chevron, but it is a small, old facility with low volume. We do have a new Sheetz which I am thinking of switching to. They are supposed to have high-quality fuel storage and delivery systems, but I am not sure about their fuel, as they are not listed as toptier. Anyone have experience with their fuel?

Ed

pk2 · 10-04-2009, 09:50 AM

I run a 9:1 mix of race fuel just because I kinda have to, can't afford any extra heat. We don't even have 93 cot here. I like to use chevron. Techronn is pretty legit harmless detergent. 20 odd years a ago I got a bum tank of gas from a no-name station. All it did was smell so stong and bad I discovered a leaking fuel line (good idea for leaky fuel finder...some sort of skunk additive).

Turn the question around, anybody had a big problem with less than fresh "High quality" fuel?

PK

ekam · 10-05-2009, 04:55 AM

Our Sunoco 94 oct also contains 10% ethanol. Lots of local Pcar guys switched to Shell 91 oct and they notice better gas mileage right off.

blue2000s · 10-05-2009, 06:28 AM

Check this out:

http://en.wikipedia.org/wiki/Gasoline_additive

You thought oil was a complicated mixture!

mptoledo · 10-05-2009, 06:32 AM

I noticed a drop in MPG when I was using "Clark" station's fuel ( I am guessing their ethanol mix is higher). Nothing bad with performance though, just a drop in mpg. I switched back to shell and the mpg is back up 3 to 5 mpg. Bad part is, my Shell station is in a very small town and is always .10 to .15 higher.

Quote:

Originally Posted by pk2

I run a 9:1 mix of race fuel just because I kinda have to, can't afford any extra heat. We don't even have 93 cot here. I like to use chevron. Techronn is pretty legit harmless detergent. 20 odd years a ago I got a bum tank of gas from a no-name station. All it did was smell so stong and bad I discovered a leaking fuel line (good idea for leaky fuel finder...some sort of skunk additive).

Turn the question around, anybody had a big problem with less than fresh "High quality" fuel?

PK

pk2 · 10-05-2009, 07:46 AM

Quote:

Originally Posted by blue2000s

Check this out:

http://en.wikipedia.org/wiki/Gasoline_additive

You thought oil was a complicated mixture!

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I noticed "toluene" on the list as an anti knock additive. Never had a knock but that's just because the timing will be automatically retarded, but that will effect performance. I use Toluene in a pinch to up the octane, It has debatable burn characteristics but it is cooler.

That's strange the higher oct. gives worse mileage. Here in CA we get to set the standards for some 12 other states(sorry) (instead of looser fed standards). I thought we oxygenated with alcohol everything, 87-91 oct. No escape. It use to be just a summertime thing but I think it's year around now.

Is performance wonder how much performance is effected with 91 oct.

Regards, PK

blue2000s · 10-05-2009, 09:48 AM

Quote:

Originally Posted by pk2

--------------------------------------------------------------------------------
I noticed "toluene" on the list as an anti knock additive. Never had a knock but that's just because the timing will be automatically retarded, but that will effect performance. I use Toluene in a pinch to up the octane, It has debatable burn characteristics but it is cooler.

That's strange the higher oct. gives worse mileage. Here in CA we get to set the standards for some 12 other states(sorry) (instead of looser fed standards). I thought we oxygenated with alcohol everything, 87-91 oct. No escape. It use to be just a summertime thing but I think it's year around now.

Is performance wonder how much performance is effected with 91 oct.

Regards, PK

For anyone unfamiliar, octane rating is a measurement of the energy it takes to start a gasoline to burn, the energy content is the amount of energy that will be released when it does burn. There's no direct correlation between the two.

Different refiners use different mixtures to increase a fuel's octane rating some of these additives have higher energy contents than others. But in general, the additives they use to increase the octane rating has a lower energy content than the gasoline itself. This is what typically leads to the lower fuel economy.

d18mike · 10-05-2009, 09:57 AM

This from The Baltimore Sun last week ... a sign of the times ...

Excess Ethanol Blamed in Breakdown of Police Cars

City officials say an unusually high concentration of ethanol in the city's gasoline supply contributed to the breakdown of more than 70 police cars over the weekend, most of which had been repaired and returned to service Tuesday.

More than 200 police cars fueled up at a 24-hour, city-run gas pump by the Fallsway before cars started showing problems, and nearly one-third of the Police Department's patrol contingent was sidelined with engine trouble.

Police doubled up in cars before activating a reserve and shifting administrative vehicles into service.

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Where I live in Michigan I can not get ethanol-free gas. And given the investment in ethanol that oil companies have made in the past year, it's hard to imagine that the 90/10 mix won't be the rule further afield in the next few years.

It will be interesting to see if there is a large enough market for one of the major oil companies to sell a premium Sports Car fuel (100% gas).

My strategy at this point is to simply stick with the major brands (Shell, BP, Chevron, Sunoco) and the highest Octane I can get locate.

yellowboxster01 · 10-05-2009, 10:19 AM

It's possible here to find gasoline that doesn't have ethanol. They usually have a large sign outside that says, "100% gasoline sold here". A few stations here also have both. Although it does cost more for pure gasoline, I've noticed a change of about 5mpg switching between them.

I asked my mechanic a while back if there were any adverse effects to using ethanol fuel and he told me that over time it will etch the inside of the tank and send metal shavings through the fuel system. There happened to be an older Porsche there that they were flushing the lines and changing the fuel filter. I was skeptical to his claims until he showed me the fuel filter and to my surprise there were metal shavings. They also showed me the waste bucket from flushing the lines and there were little metal shavings all over the bottom of the bucket.

I can't think of anything else that would cause such a thing. I've since switched to using pure gasoline.

mptoledo · 10-05-2009, 10:44 AM

I asked the mechanic (at the dealership I ran) the difference between an ethanol and gas vehicle. He told me that the ethanol car had a different lined tank, fuel lines and special gaskets as the ethanol was more corrosive than gas and would eat through normal lined parts. I know its only 10% mix(in most cases) but as the rest have said it can damage your car over time.

blue2000s · 10-05-2009, 11:00 AM

Ethanol is a solvent and will react with some plastics. Cars made in the 70s and before weren't designed with ethanol in mind and so it's use may cause damage to fuel lines and seals. It also absorbs moisture more easily, so if it sits in a gas tank for a long time, it can encourage the formation of rust.

All modern cars are designed with ethanol-safe materials. There's no risk of damage to your Boxster directly related to using 10% ethanol in your gasoline. It will lower gas mileage, though, due to it's lower energy content.

mptoledo · 10-05-2009, 11:32 AM

Only a car that states e85 ready or flex fuel is truly compatible with ethanol. As stated before cars(even 2000 model cars) are not fully able to run ethanol over a certain %.
Ethanol is a hoax perpatrated by our politicians to get the midwest vote. It is less fuel effecient and if you actually take the amount of water and energy to make ethanol, you are better off with gas only. The amount of polution given off to make ethanol is much greater than the savings it claims as burning cleaner than gas..

blue2000s · 10-05-2009, 11:50 AM

Quote:

Originally Posted by mptoledo

Only a car that states e85 ready or flex fuel is truly compatible with ethanol. As stated before cars(even 2000 model cars) are not fully able to run ethanol over a certain %.

All cars from about 1985+ are compatible with 10% ethanol. Only cars designed for E85 have ignition and fueling systems able to recognize and operate the engine on E85.

Quote:

Originally Posted by mptoledo

Ethanol is a hoax perpatrated by our politicians to get the midwest vote. It is less fuel effecient and if you actually take the amount of water and energy to make ethanol, you are better off with gas only. The amount of polution given off to make ethanol is much greater than the savings it claims as burning cleaner than gas..

I like to keep out of political conversations, everyone's right and there's never a resolution.

pk2 · 10-05-2009, 06:21 PM

Blue200s,
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Quote:

Originally Posted by blue2000s

For anyone unfamiliar, octane rating is a measurement of the energy it takes to start a gasoline to burn, the energy content is the amount of energy that will be released when it does burn. There's no direct correlation between the two.

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Nailed, got me. So whats your take on %100 octane unleaded race fuel? Fortified with "Red-Bull" & "thunderbird" " or something of substance?

And as far as additives go, where does toulene rank? whats better?
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Quote:

Originally Posted by blue2000s

Different refiners use different mixtures to increase a fuel's octane rating some of these additives have higher energy contents than others. But in general, the additives they use to increase the octane rating has a lower energy content than the gasoline itself. This is what typically leads to the lower fuel economy.

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So has no one figured out who blends the best stuff together? Also, if there adding bad cholesterol (additives) to make it 93, whats to keep them from adding bad cholesterol to 87 oct to make 91?

PK

blue2000s · 10-05-2009, 06:52 PM

Quote:

Originally Posted by pk2

Blue200s,
------------------------------------------------------

------------------------------------------------------------------------------
Nailed, got me. So whats your take on %100 octane unleaded race fuel? Fortified with "Red-Bull" & "thunderbird" " or something of substance?

And as far as additives go, where does toulene rank? whats better?
----------------------------------------------------------------------------

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So has no one figured out who blends the best stuff together? Also, if there adding bad cholesterol (additives) to make it 93, whats to keep them from adding bad cholesterol to 87 oct to make 91?

PK

I don't know exactly what's in Race Fuels like Sunco that makes them different, but I'd guess it's probably got alot less of the additives that are in normal gas. The higher percentage of fuel allows it to have more energy content. It also keeps it from cleaning your engine and shortens it's shelf life.

If all else were equal, there's no point in buying a gas for a higher octane rating than 93 (or 91 for us at higher altitude). Porsche's set the compression, ignition and valve timing to work most efficiently at 93 octane. Using a fuel with a higher octane rating doesn't gain anything. Having said that, if a race fuel has more energy content, you will get more torque from the engine. You will also increase stresses on components and increase the temperature of the engine and cooling system.

The additives in a particular gasoline are what make up the different grades/octanes. BP, for example, starts with the same base and adds different things to it to make it low, mid, or high grade. In fact, mid grade is a 50/50 mixture of low and high grade often mixed at the pump.