Crap Petrol

[vernon.taylor]

Salut

Went to see the in-laws at the weekend, and as they live at the end of twisty country roads I went in the Plus 2. Filled up on the way - I think it was a BP garage - I bought 'Ultimate' SP98 (Sans Plomb - unleaded). I'd always filled it up with supermarket petrol - closer, cheaper, and I figured it was the same stuff. Well, it isn't - or something unblocked in the carbs. It took a few klicks but then the BP stuff kicked in and God descended from heaven and blew on my TC - what a transformation! Engine much smoother and the slight acceleration lag disappeared. Engine was still running a little rich as there were still decelleration pops in the S4 twin silencer that the PO fitted.

Is this common knowledge or experience?

@+

Vernon

[DavidLB]

The super market stuff is very much lower quality, not so many additives etc, so I'm informed by someone in the industry

[Steve G]

I only use Shell V-Power or BP Ultimate in my Elan and previous performance cars that I care about. Not only do they run better on the higher octane (if set up for it) but the detergents do a good job of keeping the fuel system clean. The diesel Focus gets whatever is lying around as it's 90bhp is independent of what is in the tank, pretty sure it would chug along on sweet crude.

An informed person once told me that it all leaves the fuel depot as the same petrol, but they put an additive package in the tanker 'en route'. This increases the octane rating and adds all the other expensive detergents etc. They can actually change the petrol from the standard grade to premium if the tanker is redirected or order changed. I doubt they can change it back though!

Apparently Tesco 99 has an unusually high ethanol content and as you are no doubt aware this doesn't favour older engines. It can cause vapour lock, fuel starvation, bad hot starting etc. in hot weather and also corrodes many metals and seals and gums present in the engine and fuel system. It's a very cost effective way of bumping up the octane rating of low grade base stock though.

Looking at their own specs it looks like 5% ethanol but 35% ethanol/methanol/butyl alcohol content.

From here:
http://www.tesco.com/Momentum99/product ... -specs.asp

Sales Specification Units Min Max
Research Octane number (RON) - 99.0 -
Motor Octane number (MON) - 87.0 -
Lead content mg/l - 5.0
tah Kg/m3 720.00 775.0
Sulphur content mg/kg - 10.0
Oxidation Stability minutes 360.0 -
Existent Gum (solvent washed) mg/100ml - 5.0
Copper Strip Corrosion (3hrs at 50?C) rating - Class1
Hydrocarbon Type content

Sales Specification Units Min Max
Olefins %(v/v) - 18.0
Aromatics %(v/v) - 35.0
Benzene content %(v/v) - 1.0
Oxygen content %(m/m) - 2.7
Oxygenates Content %(v/v) - -
Methanol %(v/v) - 3.0
Ethanol including bioethanol %(v/v) - 5.0
Iso-propyl alcohol %(v/v) - 10.0
Iso-butyl alcohol %(v/v) - 10.0
Tert-butyl alcohol %(v/v) - 7.0
Ethers (5 or more C atoms) %(v/v) - 15.0
Other Oxygenates %(v/v) - 10.0

[jimj]

Always choosing Shell V max or BP Ultimate normally, a few months ago I needed petrol urgently and used Murco superior, supposedly 98 ron, and the car pinked furiously even though it runs Ok normally on regular fuels. I shan`t do that again.
Jim

[cal44]

Talk about crap gas............live in the socialist state of California.

This is where the sandal wearing tree huggers, with the blank look in their eyes, think fuel made from corn is better than feeding the corn to starving people.


Markets sell bread, eggs and milk............Gas stations sell gas.

[frearther]

Talk about crap gas............live in the socialist state of California.

This is where the sandal wearing tree huggers, with the blank look in their eyes, think fuel made from corn is better than feeding the corn to starving people.


Markets sell bread, eggs and milk............Gas stations sell gas.

And good old liberal NY, too. That corn crap and other schmutz means that gas in a can is good for maybe a month. the ten pcercne ethanol also hurts fuel mileage.

Art

[Carlos A]

http://www.pure-gas.org/

Buy without alcohol!

Carlos A

[Bud English]

Thanks for that Carlos. Had a station here in town and didn't know it.

[elansprint71]

Strangely, when one drives past the giant Stanlow Shell refinery, the tankers in line are not all Shell, Tesco and just about every other supplier seems to be there... including other main brands.

Having said this, I have always used Shell Optimax (now V-Max), simply because it did not seem to like some other stuff when I tried it.

Ah.... I remember using 5-star at six shillings and sixpence a gallon- that's UK gallons, not puny US gallons, boy!

[mark030358]

Tiz the aditives that count...

My friend worked at Thornton reaserach, Shell Ellesmere port...

Always use good stuff...

[bcmc33]

An informed person once told me that it all leaves the fuel depot as the same petrol, but they put an additive package in the tanker 'en route'. This increases the octane rating and adds all the other expensive detergents etc. They can actually change the petrol from the standard grade to premium if the tanker is redirected or order changed. I doubt they can change it back though!

I was also informed that tankers of all brands leaving our local distribution terminal had the same petrol in them - I have often wondered why the Shell/BP 98 octane I use in my regular cars appear better than the Tesco stuff have used on occasions. I was of the opinion that I was kidding myself - I will now re-assess this subjective conclusion.
However, I always try to use Shell/BP 98 octane in the Elan (plus a dose of lead additive, for luck).

[Carlos A]

Thanks for that Carlos. Had a station here in town and didn't know it.

Glad that you found a gas station that sells gasoline without ethanol. The site is quite helpful.... The best way to deal with this problem for us Classic car people is to buy this gas and support the vendors with our business.