GASOLINE More answers and insight

Some more insight on gasoline. I spent some time with the "Gas Man" this week as well as a brief conversation with one of the engineers. I had a copy of the last post with the questions in hand, so I now have most of the answers.

Let me run through the questions first.

Yargk

Do you know how Valero's premium stacks up against Chevron's premium?

Was told: Not a producer, mostly a marketing company. Not a Teir 1 supplier.

BRAINIAC

Now my question. I have a 2.4 liter T motor with 10/1 CR. Can I get away with Chevron regular? You seem to be OK with it in your SC with 9.3/1. What about mixing 50/50 premium and regular?

Was told: The regular depends on some of your variables, climate, timing advance, heat range etc. You should try it. Put in half a tank and see how it works, if she starts knocking top off with some premium. This should give you an idea for the regular, and if it doesn't work for your situation, then you will also get an idea of a 50/50 ratio. Experiment and see where it works best.

Make sure and see the comments below concerning Performance Vs. Driveability.

Bill Douglas

Where I live they have a new petrol with an additive called Vortex (just some name their marketing guys came up with I think) which cleans your valves and injectors as it goes through the system. I guess it's a bit like you guys Techron that is with Chevron ? petrol. Anyway, what happens to the stuff. Does it get burnt off and go out the exhaust pipe or does it end up in the oil resulting in some nasty sort of contamination?

Was told: Chevron has Techron
Texaco has System 3

These are the names of their additive packages, and they use the name for marketing. Shell does not use the name of their additive pac (Vectron) at least not in the US. I wonder whose gasoline Vortex comes in, Shell?

What happens to the stuff?

It depends on the engine. The "tighter" the engine is the deposits go through the exhaust system. The more wear that is on the engine, the greater likelihood for them to find their way in to the oil.

Question/comment number two: A scientist guy I worked with who also races motorbikes (so a reasonably educated opinon) says our New Zealand 91 octane petrol is beter than our 96 because 96 is the same stuff but with more additives to stop pre ignition, and that 91 is beter bacuse it compusts faster and therefore
more efficently than the 96 petrol.

Here is some good info:

Regular is easier to ignite then premium. Ideally gasoline is compressed, and ignited by the spark plug. Pre-ignition is when the gasoline combusts before the plug fires attempting to make the engine run backwards, resulting in the knocking. This is usually the result of the cylinder being hot, and the gasoline being compressed to a point where combustion occurs, much like a diesel engine or the small model airplane engines with the glow plugs.

For increased performance you want to create a more powerful explosion. This is done by increasing the compression ratio or literally compressing the fuel vapor tighter. However you will now need a gasoline that can tolerate the higher pressure without being ignited except by the fire from the plug. Premium can do this to a degree.

Regular Vs Premium

Regular is much better for "derivability" then premium.

Premium is much better for performance then regular, under the right circumstances.

OEMs often recommend regular, why? Because this is what the engine was designed for. The compression ratio, the timing as well as many other considerations were designed around the characteristics of regular fuel, to create the best circumstances for the combustion to occur. When everything else remains the same, but you use a premium gasoline, that resists combustion at that point you cause derivability issues.

Performance may be great, if the engine is on the track and operating in the upper RPM range continually. However the street car stopping in traffic and at red lights may find itself stumbling, or bogging on take off because the gasoline doesn't explode when it should, or at least when it was designed to.

For the best derivability for the turbo cars abroad it is recommend to find the gasoline with the highest RON number, yet the lowest MON number. I don't know how you can do this, but that was the advise from a research engineer. I know here in the US the displayed octane rating is the average between RON and MON, and everyone else uses a different method, I don't know is revealed at the label on the pump.

ServerDude

I used to think Sunoco had a little extra "goodness" because you can get 94 octane as opposed to the regular 93. But I also noticed that on the Sunoco pumps, there is a label indicating usage of something like ethanol, methalyne, proto-tetra-ethyl-mono-super-duper-alco-ethyl-bi-butane-I don't know. But it indicates that their additive has some non-petro based fuel component. No big deal typically - but I also heard along the lines somewhere - and it might be in my owner's manual (have to check) to never use fuels with said additives.

This is basically a "Pissing match" between OEMs, Government regulators, and the Oil Companies.

The government requires it be added, the oil companies are required by law to add it, but the OEMs say don't use it.

How can you get around it?

The CRC, Coordinated Research Committee has been trying to get the OEMs to drop this "advise", but in the mean time they all keep pissing on each other.

I still think Exxon sucks. ME TOO!! (That was a question right??? Well that's my answer)

Zakcruz

I have a question about MTBE. I haven't used the Union 76 gas but was sorry to hear that it's not on the A list because here in Santa Cruz County they are the only stations where we can buy MTBE free gasoline. Instead they use the good 'ol Ethanol additive. Environmental issues aside, which additive is best for my car? And what are the effects of these two additives?(I currently use Chevron or Shell prem.)

I was told:

MTBE is the additive of choice, although both serve the same purpose of "oxygenating" the gasoline. It has been properly pointed out that MTBE is being phased out for environmental reasons. Other substitutes are being looked into, but ethanol is an available alternative, and a quick fix if needed.

Feelyx

I would have to think that gas companies, like car companies, are into production and cost savings, and you aren't always getting what you pay for. So, to compensate, I add an additive. It's call energy release made by entech, www.energyrelease.com has your testing facility tested it at all? I am curious because when I tore down my 944 to put in a new head gasket, the valves and piston tops where clean. (112,000 mi.) I do use union 76 (a dirty gas as you listed) I would like to know if the stuff is good or is it another smoke and mirror job. (I certainly wouldn't have a problem spending the money somewhere else)

Most of the research on additives is done in preparation for developing an additive on a large scale, and there has not been any investment made into evaluating this additive or the Z Max.

They are considered "Favorable" but there is no test data to support it.

Union 76 has not been tested at the lab. Most of the fuels tested are from the Houston area, and 76 is not a player here. There is testing done from other areas, but it is usually initiated by a rash of dealer reported fuel problems. Union 76 is not a Tier One supplier.

Paulhagedorn

Oh, and MTBE is actually a good thing...it helps clean deposits in engines and helps the gas to burn cleaner and more efficiently.

Correct, except efficiently. MTBE does cost MPG, 8-12%

Part of the reason MTBE is being phased out is that the underground gas tanks that gas stations have leak....some of them were designed to leak?? i think. Legislation is to get rid of MTBE instead of fix the leaking gas tanks, go figure.

VERY CORRECT!!

gaijinda

I once read that the reason why mixing leaded gas with a unleaded premium gave such a high octane rating was that unleaded premiums are made of better "stocks" of gasoline. (Naturally higher octane rating.)And these better stocks react better to lead and therefore adding a small amount of leaded gas (gave) you a large
boost in octane rating.

Same Base Fuel different additives.

Automahn

Ok I do have a question I have been running chevron supreme with techron. The previous owner only ran this in the car. Am I wasting my money on the premium? Would my car notice the difference if I was to go to regular. I also have an 81 911SC that is 100% stock and it is a california car.

Techron is the same package in all three grades of Chevron gasoline. I would try the regular and test a little, but it should work fine.

GT911,

Below is a DIY guide to boosting octane. Can you check the accuracy and reliability of this info with your tech guys.

Fuel Formulas
Please note that I would NOT suggest that a person use the following fuel mixtures without considering the detrimental effects on their engine, vital engine components (O2 sensor, etc), and other potential damage. That said, the information is interesting.


Fuel Formulas
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Original publication is:
GS-Xtra
1213 Gornto Road
Valdosta, GA 31602
(912) 244-0577

Editor: Richard Lasetter, president Gran Sport Club of America (GSCA)
The title of the original was something like "Homebrew Octane Boosters"... I
took a little license in adding some things to the article from my experiences
when I typed it in, so it isn't verbatum, but most of the info came from Rich.

Formula #1 - Toulene
=============================

R+M/2.........114
Cost...........$2.50/gal

Mixtures with 92 Octane Premium
--------------------------------
10%...........94.2 Octane
20%...........96.4 Octane
30%...........98.6 Octane

Notes: Common ingredient in Octane Boosters in a can. 12-16 ounces will only
raise octane 2-3 *points*, i.e. from 92 to 92.3. Often costs $3-5 for 12-16
ounces, when it can be purchased for less than $3/gal at chemical supply houses
or paint stores.

Formula #2 - Xylene
=============================
R+M/2.........117
Cost...........$2.75/gal

Mixtures with 92 Octane Premium
--------------------------------
10%...........94.5 Octane
20%...........97.0 Octane
30%...........99.5 Octane

Notes: Similar to Toulene. 12-16 ounces will only raise octane 2-3 *points*,
i.e. from 92 to 92.3. Usually mixed with Toulene and advertised as *race
formula*.

Formula #3 - Methyl-tertiary-butyl-ether (MTBE)
=============================
R+M/2.........118
Cost...........$3.50/gal

Mixtures with 92 Octane Premium

--------------------------------
10%...........94.6 Octane
20%...........97.2 Octane
30%...........99.8 Octane

Notes: Oxygenate. Very common in octane booster products. Has lower BTU
content than toulene or xylene, but oxygenate effect makes the gasoline burn
better and produce more energy.

Formula #4 - Methanol or Ethanol
=============================
R+M/2.........101
Cost...........$0.60 - $1.75/gal

Mixtures with 92 Octane Premium
--------------------------------
10%...........94.3 Octane (Methanol)
10%...........94.7 Octane (Ethanol)
20%...........Not Recommended

Notes: Methanol is wood alcohol. Ethanol is grain alcohol and found in Gasohol
in 10% ratios. Both alcohols are mildly corrosive and will eat gas tank
linings, rubber and aluminum if used in excessive ratios. Main ingredient in
"Gas Dryers", combine with water.

Formula #5 - Isopropyl Alcohol and Tertiary Butyl Alcohol
=============================
R+M/2.........101
Cost...........$0.60-$1.50/gal

Mixtures with 92 Octane Premium
--------------------------------
10%...........94.5 Octane
20%...........Not Recommended
30%...........Not Recommended

Notes: Similar to Methanol/Ethanol. Isopropyl Alcohol is simply rubbing
alcohol.

How to make your own octane booster (this is the basic formula of one of the
popular octane booster products). To make eight 16 ounce bottles (128 oz = 1
gal):

100 oz of toulene for octane boost
25 oz of mineral spirits (cleaning agent)
3 oz of transmission fluid (lubricating agent)

This product is advertised as "octane booster with cleaning agent *and*
lubricating agent!". Diesel fuel or kerosene can be substituted for mineral
spirits and light turbine oil can be substituted for transmission fluid. Color
can be added with petroleum dyes.


Original by:Kyle Hamar

I have also found this site which gives a good short overview on octane requirements:
http://www.osbornauto.com/dragster.htm

This is a link to a much more technical article. I gave up after the first part:


Btw GT911, do your findings on gas companies apply worldwide too eg. is acompany that's good in the USA also good everywhere and vice versa?

I appreciate all the info you've been providing. I used to always fill up at Mobil, now I've switched to Texaco (it's the only company you mentioned that's in the area).
I have a question about the sampling.
Is the gas that is used purchased only from one area? What I mean is, when you/they buy Texaco gas, is it only purchased from one station, or do you/they go around to random Texaco stations to "fill up"?
I'm not sure you can generalize to the point of saying, "because we found gas from 1 station to leave a significant amount of deposits, that all gas from all the same brand stations will give the same result".
If you get the gas directly from the supplier... before it goeas anywhere, then I'd be much more inclined to accept the generalization.
Thanks,

------------------
Dan Tolley
1987 911 Coupe
http://www.cheaterswayside.com/911/gallery.asp?sort=0&userid=294

They buy the gas from the supplier, not at the station.

Typically they put 10,000 miles on the engine, at an average of 300 miles per tank it will require 33.33 tanks. If a tank is 15 gallons you will need 500 gallons. It only takes a week or two to run a test in the dyno. They buy all the gasoline up front at one time.

When an additive package is added, it is the same for all the gasoline of that supplier in the area, because the same trucks distribute the same fuel. The variation will be in the "Base Fuel" that the additive package in put into, it may vary, but quality gasoline suppliers use a better additive package to compensate for poor quality base fuels, spot market suppliers do not.

Some small independent dealers have been known to buy spot market fuel and put it in their name brand gas stations to cut corners. I mentioned an example where it was reported that one Shell station had poor quality gasoline, and samples were taken and found that all three tanks were full of regular, and none of it was Shell gasoline. This is a very rare occurrence, but it did happen, and it was corrected.

What kind of quality controls do you think the supermarket type stations have in place?

I also mentioned "in the area" because quality suppliers do fine tune their gasoline for different regions based on temp, altitude, humidity etc.. The gasoline supplied to the Denver area is different then that supplied to South Florida. Same good quality fuel with the same cleaning agents, just modified to work best in the climate it is used. Spot market suppliers do not make these type of adjustments