Unleaded fuel question

Hoping for some advice. Firstly, I have read a few entries in the forum about which fuel to use. Just for my own peace of mind, can someone confirm that I can run my 1984 1.8GTI Cabby on Premium Unleaded. At the moment I am using LRP, but that is getting harder to come by. Secondly, is it ok just to add the unleaded onto what remains of the LRP in the tank, or does the tank need to be empty first (or close to it)? Lastly, is it true that the fuel from supermarkets is inferior to that from the likes of Shell/BP etc?

Many thanks.

Welcome to the forum Lee.

I believe Esso and Texaco do the best quality fuels on the market.

A standard MK1 GTI should be running RON98 fuel. This can be bought from Shell(Optimax) but some engines can cope with BPs RON97 Ultima without 'pinking' - predetonation.

Alternatively, you can have the ignition timing adjusted from 6 degrees to 0 degrees (check what the mechanics, who serviced your car last, set it at). This will allow a slightly longer burn time so you can use RON95 fuel. Some engines may not like it though and will 'pink' so this may not be an option. This method will loss some power.

There is another option too. You can buy aftermarket electrical gizmos like V-Sam which alters the ignition timing(?) and allows you to run RON95 and GAINING slight power. But its costly.

The lead in petrol had two functions - to raise the octane rating, and to protect the valve seats in some engine's heads.

All VW's made after the early 70's have valve-seats hard enough to use unleaded, so that just leaves the octane as an issue.

GTIs need 98 RON when the timing is set to factory settings, but if you retard the timing, you can use 95 unleaded, but there will be a noticeable loss of power.

You can fix this with liquid additives to the fuel, or by using a solution like V-Sam or K-Star, which do alter the timing, as mentioned above.

There is no problem mixing LRP fuel with anything else, once you don't do anything that means that you have a tank of mostly 95 RON fuel, and the timing isn't retarded. If you experience pinking (aka knocking, pre-ignition), it won't ruin the engine immediately, but don't drive it hard, or with a full load in the car until you've done something to eliminate it…

Thanks for the advice. I have a feeling that there will be many more questions in the months to come, so its good to know that there are people out there willing and able to help. Cheers.

I got a FUEL CAT on mine, I really could`nt live with out it.
http://www.fuelcat.co.uk/

I bought it for my astra a year ago and now have it on my golf, 95RON to 98 RON its like running shell optimax all the time.

one thing i have noticed was it took time to bed in though but after a few K on the clock the engine was very responsive. I had to adjust the ingnition timing a little till i got a good balance.

Mind u iam running a SPLITFIRE also on BOCH super 4s
http://www.fuelcat.co.uk/multispark.html

In independant tests of the fuel cat thingies in the 90's there was no measurable benefit found.  Sure your not getting a placebo effect?  

Yes agreed i have read the reports from the RAC and there was an admendment

Amendment made on 4 May 2001
It should be noted that the RAC was commissioned by the ASA to produce a report commenting on the claims made by Clockwork Orange Limited in relation to Fuel Cat. The RAC did not, as far as we are aware, carry out any tests on Fuel Cat. However, the RAC report did conclude: 'None of the claims made by Clockwork Orange Limited in respect of Fuel Cat have been substantiated. Furthermore, there are good theoretical considerations and existing knowledge which lead to the conclusion that tin alloy pellets in the fuel tank of a vehicle or fitted in the fuel line, with or without a magnet, will not have any effect on combustion and therefore cannot affect fuel consumption, exhaust emissions, gasoline octane number, exhaust valve seat recession or exhaust catalyst life.'

http://www.oft.gov.uk/News/Press+releases/2000/PN+42-00.htm

and then Fuel Cat never cam up with any proof… and after reading many articles i do belive there is somthin in it…this guy sums it up>

The latest tests are on a Ferrari 328 GTB which is regularly driven at various race circuits including Silverstone and Brands Hatch. The owner of the Porsche 944S, shown in the "Gallery", was so impressed with the improvement that he recently fitted a Fuel Cat on his
Ferrari. Being a computer entreprenuer with over 20 years experience in computing, the owner wanted to back up his confidence in Fuel Cat with scientific computer analysis.
A rolling road test was performed immediately before fitting the Fuel Cat. And a few days later at Castle Combe race circuit the Ferrari performed magnificently. The Ferrari has continued to perform exceptionally well at      Silverstone, Oulton Park, Brands Hatch, Donington Park and on Jonathan Palmer's new Bedford Autodrome     circuit near Thurleigh. The Bedford Autodrome was    officially opened on 3rdAugust 1999 and the RMA      organised the track time. Following a season of track days the car performed so well that the owner felt he did not need to pursue a further rolling road test -quote: "I know the  Fuel Cat works, so I don't need to subject the car to the stress of another rolling road test. And it is not just my opinion -my Ferrari mechanic also commented that the engine seems a lot better now than a year ago when he last drove it!"

tell u the truth is a suck it and see device. at first it makes no difference.

then the DTI done a test>>

http://www.broquet.co.uk/dti_test.htm

another Lab test
http://www.carbonflo.com/objective%20report%20files/objective%20reports.htm