Unleaded question?

[streetboy]

Today I pulled up to the pump at my local garage and then realized the run of the 'run of the mill' unleaded that I normally use was out of order. So I stuck £20 of super unleaded in instead as I was late for work.
The tank was almost empty and I have noticed a real difference in how the bus was running straight away. Much smoother at idle and seems to generally run much better all round.
Has anyone else noticed their buses running better on the expensive stuff?

 

[toffo24]

I run Super in my 205 and the camper The higher octane helps with the older engines much nicer to drive!

 

[robjarman]

i tried BP Ultimate for a while - seemed very good - then someone told me it was bad for our air-cooleds with valves burning out or something - is that correct? as I never seemed to get a better m.p.g. anyway, I reverted to ordinary unleaded...
Rob

 

[streetboy]

i tried BP Ultimate for a while - seemed very good - then someone told me it was bad for our air-cooleds with valves burning out or something - is that correct? as I never seemed to get a better m.p.g. anyway, I reverted to ordinary unleaded...
Rob

I've been reading back on some old threads about unleaded with some interest. I think from 1967 all vw engines were designed to run on unleaded, it was a requirement in the U.S, but not 100% about Uk buses?

There was a company that tested fuels from 95 to Tescos 99 ron and their finding appear to prove that the higher octane fuels will improve running and preformance. And the Tesco's fuel came out on top by far :shock:

My bus deffo feels better for it, just not me wallet :lol:

 

[Loxy]

i tried BP Ultimate for a while - seemed very good - then someone told me it was bad for our air-cooleds with valves burning out or something - is that correct? as I never seemed to get a better m.p.g. anyway, I reverted to ordinary unleaded...
Rob

I've been reading back on some old threads about unleaded with some interest. I think from 1967 all vw engines were designed to run on unleaded, it was a requirement in the U.S, but not 100% about Uk buses?

There was a company that tested fuels from 95 to Tescos 99 ron and their finding appear to prove that the higher octane fuels will improve running and preformance. And the Tesco's fuel came out on top by far :shock:

My bus deffo feels better for it, just not me wallet :lol:

Got a letter from Volkswagen & Tescos somewhere sent to the original owner as a result of his investigations into unleaded petrol and its effect on the engine, will try and dig them out.....

 

[streetboy]

Yeah do that Loxy, be interesting.

Logic just says to me the higher octane fuel has got to be better.

 

[froggy]

To start with i used a lead replacement additive and unleaded petrol, then just normal unleaded but got to admit i used super plus unleaded the other day and i agree the van just seemed smoother, more responsive. Have also tried the shell V plus but for the price i think its either unleaded or super plus unleaded for me.

 

[Loxy]

I was wrong, I didnt have a letter from VW - I had a few :lol:
Ok hopefully you can read all the hand written ones by the way the van hasnt done 70k miles(not even now) - think he meant km

Not sure that they really answered the question though :lol:

 

[streetboy]

No :lol:

from Feb to March 1998 they give three different awnsers! :shock:
use unleaded only, every 5th tank unleaded, and then good to go with up to 98 ron :?

I'm going to stick with the super for now and see how it goes. I'm pretty sure the new engine has unleaded heads.

 

[Loxy]

I'm going to stick with the super for now and see how it goes. I'm pretty sure the new engine has unleaded heads.

I'm not aware of anyone thats had an engine die due to obvious valve seat issues/unleaded fuel.
I got the impression that the engine ran a bit cooler using the good stuff when I used it to drive across Europe but I wouldnt describe it as a scientific test

 

[toffo24]

I beleive that lead was added to petrol to stop pre-ignition or pinking (which kills the valve seat). Unleaded was brought in to replace this due to health reasons. It ment adjusting ignition timing to stop pinking when using unleaded fuel. Super unleaded is higher octane (I beleive that this is how well the fuel would burn when ignigted) hence the better running of the engine. Beleive it or not some garages used to sell 5 star petrol and octane rating of 101 ron.Caviar for cars !

Most old cars have soft metal valve seats and require lead in fuels. I always fill up with branded fuel ie, BP, Shell, Texeco. and avoid the supermarkets as I read that they dont uses some better more expensive addertives in there fuel. hence the problems tesco had a couple of years ago.

There is a diffence in the fuels as branded fuel tends to return better MPG, ( personal experience from driving 65,000 miles a year for a living)

Just my view I will always uses super unleaded 97 ron or BP ulimate or an equivalent, as it is around 102 ron to get the best from engine.

 

[BJ1]

The letter from Tesco dated 25 March 1998 is typical Tesco bollox.

I have run unleaded fuel in aircooled VWs (fuel from supermarkets and oil company stations) since 1974. I have never had problems with valves and seats, other than one beetle that had been run with tight valves for at least 20k miles by a PO (muppet).

Providing you adjust valve clearances and check timing every 3k miles without fail you will not have valve problems with any aircooled engine made after the mid 60s.

IMO valves are killed by hot engines and/or tight tappets, not unleaded fuel - period.

 

[Doris]

I notice a difference in the high octane with the Vectra, not tried it with an air cooled dub,however,always used unleaded without an issue.as has been said, I think there is a lot more common things than can reduce the life of a VW engine than the fuel.e.g lack of oil changes,valve clearances etc.

carry on...

 

[streetboy]

I'm now having a go with Tescos 99 and thus far the bus still runs better but not quite as smooth as with the BP super. I'll use the Tescos fuel up and refill with the BP again and note any differences.
No garantee I'm going to find a BP station when I need to refuel when out and about, but will be handy to know what effect various unleadeds have on the overall running.