Additive

[NWplasterers]

Good morning all !
Here's the question!
Hopefully with the weather attempting to improve I'm hoping to get some nice long drives done in the E.
However,would it be prudent to still combine a fuel additive with unleaded fuel as some of the reading I've been doing suggests that a conversion to unleaded isn't necessarily 'job done'.

Be interested in all opinions
Cheers guys !

Neil.

[Heuer]

The XK engine has a alloy head with hardened steel valve seats so it has always been suitable for lead free fuel, no 'conversion' necessary. Additives are pretty pointless unless you can't find super-unleaded fuel and want to add an octane booster until you do. You need a lot of octane booster, which is expensive, to make any real difference so drive the car gently until you can find suitable fuel. I always use Shell VPower Nitro+ or BP Ultimate or Total Excellium as they are 97+ octane (101 in the case of VPower in some regions) and contain quality detergents. You need to vigorously avoid standard unleaded fuel because they can contain up to 10% ethanol. All pumps must be marked E0, E5 or E10 to show the percentage of ethanol so look for E5 or lower.

[NWplasterers]

Thanks David
Luckily I religiously put shell nitro in it anyway,and once every three to four fill ups in the other cars also.
Thanks for your advice,feel happier now !!

Kind regards

Neil.

[Vonkie]

Seems like it makes quite a difference what compression ratio you have. The 8:1 can handle a lower octane far better than the 9:1.

We don't really get anything above 95 at pumps here...

[Nickleback]

So why not use Tesco Momentum 99 super unleaded as an option, higher RON (99) in the UK than the others with the same additives but generally cheaper to buy.

[malcolm]

I spoke to a refinery worker who told me that Tesco momentum is the same as Shell VPower nitro, just a badged version!

[cactusman]

The notion that all the brands "make" their own fuel is incorrect. The base fuel comes from a couple of refineries what ever brand you buy. We actually have few refineries left. It is blended with up to 10 % ethanol and various detergent additives etc. True, Esso may add a few different detergent additives etc to your supermarket fuel but all fuel has to meet appropriate British standards what ever the brand. All the excellium and v power is really 99% marketing hype. Here in Hemel we have Buncefield of explosion fame. If you live anywhere in west or north London and the home counties five gets you ten that you fuel came from Buncefield. All the tankers fill from the same tanks...you can watch them queue up. So whether it is v power nitro or Sainsburys super it is all for practical purposes the same stuff. Get 99RON and it is ethanol free at present.

[tim wood]

Having worked in the fuel industry for a major oil co I would support and agree with the comments from Julian.

Regards

[cactusman]

Thanks Tim...twas a big bang when the tank overflowed and was ignited...would have fuelled an e type for aeons

[cactusman]

Interestingly a peer at the shell v power page it talks about "dynaflex" technology, cleaning power and friction but a squint at the small print and even shell say, and I quote, "actual effects and benefits may vary according to vehicle type, vehicle condition and driving style. No guarantees provided". I read that as admitting that actually, their fuels do the same job as everyone else's.
I believe that the motoring organisations and government all say, with evidence to prove it, that the best way to improve fuel consumption figures is to maintain your vehicle.... e.g. ensure the brakes don't drag etc, ensure tyre pressures are correct, don't carry unnecessary stuff about and drive conservatively avoiding harsh braking and acceleration.....which we all do of course....well most of the time anyhow
Given that e.g. Sainsburys super is 10 to 15 p per litre cheaper than the branded fuels I use supermarket super ul when ever possible. Seems just fine to me.

[Heuer]

My experience with various fuels is mixed. My Alpina B5 (supercharged and turbo) performed oddly on Shell V-Power with a lumpy tickover and hesitancy, something the other B5 owners agreed with. Filling with BP Ultima solved the problem. My Range Rover Sport performs stunningly on Shell V-Power diesel with better fuel consumption, smoother tickover and more power. My E-Type does not like 95 octane fuel at all although I now have a switchable map on the EDIS/Megajolt to compensate when I can't get Super. I just use any Super regardless of source. Best performance I ever had from the E-Type was when I filled it with 101 octane leaded fuel - it was available from a few garages some years ago. Basically they used super unleaded a base and added lead. The cost was frightening though so I only did it once.

[tim wood]

Hi Julian,
The bang certainly was loud, rattled our windows 20 miles away.
Luckily I wasn't duty engineer that weekend !

Tim

[cactusman]

For those happy to pay extreme prices one can always use avgas that still contains tetraethyl lead. 100 octane and about £1.60 to £2 or more per litre. Spoke to a chap who filled up on avgas once and his e went like a rocket. Not really a practical everyday option though..

[Gfhug]

And where are you going to get avgas? Drive your car airside at even a small airfield and your insurance will most likely become invalid. Read the small print. And even small airfields probably won't let get to the pump or bowser. Reminds me of the chief instructor where I learnt to fly who would fill his XJ6 with avgas.

Now if you could get the 130 octane avgas, imagine what that would do for you

Geoff

[cactusman]

It is (or was) available at Silverstone

[abowie]

100LL Avgas is available from a couple of suppliers in my home town, in addition to being available at several airfields. The only problem is the price; around $3.00 per litre.
It certainly does make LBSCs go well and gives you that lovely pale grey inside the exhaust.

[44DHR]

Avgas 100LL is certainly available to purchase from airfields in the U.K. - probably more accessible at smaller local fields than than say turning up at Heathrow ! You don't take your car airside, but rather take 20 litre Jerrycans to the pump, as running a car directly on Avgas would be rather extreme.
I buy my Avgas 100LL from my local airport on the Isle of Wight and use it both as an "additive" for the E Type and more importantly for my old Spanish Trials bikes as these have fibreglass fuel tanks which could be softened or even destroyed by the ethanol in current petrols.
The last time I stocked up was in April 2017 and it was £1.66 a litre. Smaller airfields have unattended self service pumps due to the nature of aircraft movements and have a procedure to fuel which can be easily followed. As aircraft would be fueling in larger quantities, our pumps operate once you insert your payment card and get pre-authorisation to a maximum value. Once authorised, you take as much fuel as you require within that limit and re-enter your card after fueling to obtain a receipt of actual fuel taken.
The other advantage of Avgas is it has - again by its very nature - the ability to be stored for longer periods without going "stale".
Without meaning to start a debate on the benefits of higher octane fuels, the octane rating is not a measure of the energy stored in a fuel, it is the measure of the resistance of the fuel to detonation, which becomes of interest in our higher compression engines.
Regards,
Dave

[NWplasterers]

So ok.
Despite my original post I'm kind of intrigued by the Avgas scenario! I live 5 minutes from Brands Hatch,where can I get me some Avgas then ?!?!

Neil.

[PeterCrespin]

my old Spanish Trials bikes as these have fibreglass fuel tanks..

In order of likelihood for old bikes I'll guess Bultaco, Montesa, Ossa?
bit more modern would be SWM, Gas Gas?

[Moeregaard]

It's worth mentioning that 100LL has three to four times the lead that any automotive petrol ever had, so extended use can lead to deposit issues in automotive engines. There also may be legal troubles, as is the case here in the states regarding road tax and environmental issues. Most recently, I showed up at our local airport with a couple of jerry cans in the truck and they told me that they couldn't legally sell it "over the counter" anymore. It does smell nice while turning the inside of your tailpipes that nice light-grey shade though...