Petrol additives

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Dave Wheatley
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Joined: Fri Sep 28, 2018 4:55 pm
Forename: Dave
Surname: Wheatley
Location: SW Scotland

Petrol additives

Post by Dave Wheatley »

Now that we have had E10 fuel for a few weeks, can anybody point me to reviews of the various (lead replacement, octane boosting, anti ethanol) additives. Hopefully by now some classic car magazines or organisations will have produced reports.
Additives any good?, or snake oil.
Any personal experience on here?
Any recommendations?
I can only get E10 round here.
1978 MGB GT
1967 Morris Minor convertible
1955 Standard 10
1972 Ford Cortina
No modern!
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Bumpa
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Forename: Mike
Surname: Howlett

Re: Petrol additives

Post by Bumpa »

Don't any garages near you stock the super grade? Super unleaded is going to remain at not more than 5% ethanol, and some brands are zero. Round here (Ayrshire) its only Morrisons that don't keep the super grade. All the other supermarkets and small garages have it. OK it costs more but with low mileages covered by most classics it's not a big extra expense.
Mike
1969 MGB GTV8 3.9 Conversion, 1977 Triumph Dolomite 1850HL, 1971 MGB roadster undergoing restoration.
Dave Wheatley
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Re: Petrol additives

Post by Dave Wheatley »

It's a 50 mile round trip to the nearest E5 stockist at Newton Stewart. I made a special trip there last weekend, and they didn't have any!
An additive that works would be welcome.
1978 MGB GT
1967 Morris Minor convertible
1955 Standard 10
1972 Ford Cortina
No modern!
Ian Fozzard
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Re: Petrol additives

Post by Ian Fozzard »

Dave, take a look at this from the fbhvc:

https://fbhvc.co.uk/fuels

Whether you need "lead replacement" additives depends on your specific engine and whether you have had hardened exhaust valve seats fitted. I used to use the Castrol additive and as far as I could tell it worked fine.

Ian F
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
Dave Wheatley
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Joined: Fri Sep 28, 2018 4:55 pm
Forename: Dave
Surname: Wheatley
Location: SW Scotland

Re: Petrol additives

Post by Dave Wheatley »

Thanks for that excellent link Ian. I'll give it a good perusal before supper.
"and as far as I could tell it worked fine." - this is the problem with these additives which is why I could do with reports from organisations like the FBHVC.
1978 MGB GT
1967 Morris Minor convertible
1955 Standard 10
1972 Ford Cortina
No modern!
Ian Fozzard
Posts: 655
Joined: Fri Mar 27, 2015 8:18 am
Forename: Ian
Surname: Fozzard

Re: Petrol additives

Post by Ian Fozzard »

I suppose what I was saying is that I had no discernable valve seat recession when using the Castrol additive - didn't have to adjust the valve clearances and the seats looked Ok when I stripped the head.
Of course the damage potential of ethanol is much more difficult to assess as it could extend throughout the fuel system and affect several different materials.
I am fortunate (here in Fife) as I have Shell station nearby and always use their Super Grade.

Ian F
1972 BGT, Blaze, Navy trim, recessed grill
1961 Midget, 948cc, Clipper Blue, Blue trim and weather gear
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Peter Cresswell
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Re: Petrol additives

Post by Peter Cresswell »

I did suffer from quite sudden and severe valve seat recession (over about 1000 miles) when we took the B to France in 2017, and this was despite using Castrol Valvemaster since I bought the car at the end of 2011, and running it on super unleaded. I think the underlying reason was constant speed cruising on the Autoroutes. I then built a new engine using another head and had unleaded valve seats fitted as part of the upgrade.
I haven't got much more advice to offer to all the good stuff above, but remember E5 fuel has between 0 and 5% ethanol but E10 has between 5.1% and 10%. This means E5 might not have any ethanol in the fuel but E10 will always contain ethanol. Esso have recently issued a statement that their Supreme + fuel contains no ethanol in most parts of the UK. I believe Shell and BP have some ethanol in them as I haven't seen them claim it is zero.

Also remember the MGB engine was designed to run on 98 Octane minimum so they should have always been fed with 4*or Super Unleaded fuel, but the bad effects of ethanol fuel will not be seen for some time as it takes time for the ethanol to degrade (for example) the fuel hoses. You might notice E10 affects the way the car runs as the stoichiometric ratio is lower than for pure petrol. Modern cars can cope with this because of the pre and post cat. sensors which are used to manage the correct fuel to air ratio. You will also get less MPG from E10 fuel over E5
Pete
1969 MGB Roadster
2020 MG HS Exclusive
2007 Mercedes SLK
Plus 34 other cars since 1965
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