Frequently Asked Questions

1. How do I obtain TetraBOOST ‘E’ Guard 15?
Order directly from our parent company, Fuzz Townshend’s Classic Oils – click here

or call 01869-227062


2. Is TetraBOOST a lead substitute?
No. TetraBOOST ‘E’ Guard 15 is genuine Tetraethyl Lead (TEL) in a solution of aromatic hydrocarbons, with its associated chemical scrubbers and anti ethanol formulations. TetraBOOST enables you to make genuine leaded fuel from the unleaded pump, wherever and whenever you need it.


3. By how much does TetraBOOST increase the octane rating?
Mixing the required amount of TetraBOOST with unleaded pump fuel to create 4 star leaded petrol increases the octane rating by 2 points. Therefore, mixing up leaded 4 star from ordinary unleaded (95 octane) will give you 4 star 97 octane. If you start with super unleaded (97 octane) this will effectively give you 4 star + 99 octane. Many customers make up 100 octane mixes for higher performance applications. TetraBOOST is capable of raising the octane up to 106 for specialist race engines. Remember that stronger concentrations do no harm to your engine. TetraBOOST recommends Shell V-Power for high octane mixes for race use.


4. Can I continue to increase the octane rating to over 100?
Yes. Unlike substitutes where too much can damage your engine, you can make stronger leaded fuel using TetraBOOST without harm to the engine. TetraBOOST is capable of raising the octane up to 106 for specialist race engines. TetraBOOST recommends Shell V Power for high octane mixes for race use.


5. Can I buy TetraBOOST from my local garage?
No. TetraBOOST is only available from distributors


6. Why do I need TetraBOOST when 4 star is being sold at some garages?
There are around 23 fuel stations selling leaded fuel in the UK. All of them are now selling TetraBOOST leaded which has been splash-blended on site. Unfortunately leaded stations are few and far between and although you may be able to start your journey, you may struggle to get back home again. Motoring abroad of course becomes an impossibility. TetraBOOST additive in the boot of your car is the only way of ensuring supplies of leaded fuel where and when you need it.


7. How far will a box of 6 x 945ml cans take me?
Assuming that you need 4 star fuel and that your car does around thirty miles per gallon, a box of 6 x 945ml cans will take you almost 4,000 miles, i.e. it will make around 700 litres of leaded 4 star fuel.


8. Does TetraBOOST represent good value for money?
TetraBOOST ‘E’ Guard 15 incorporating anti-ethanol chemistry costs less than some lead substitutes, and is much less expensive than race fuels.


9. Can I order smaller quantities?
Yes, you can order individual bottles, which are ideal for motorcycles and occasionally-used cars


10. Can TetraBOOST be mixed with leaded pump fuel?
Yes of course, if you can find any! TetraBOOST is exactly the same as the lead that used to be in pump fuel.


11. What basic pump fuel should I use?
To make 4 star leaded, mix TetraBOOST with regular (often called premium) unleaded. To make 5 star, it is more economical to start with super unleaded as your base. For higher octanes we recommend Shell V-Power, an excellent fuel typically delivering 99 octane.


12. Can I mix TetraBOOST ‘E’ Guard 15 with one of the lead substitutes?
No. TetraBOOST is a genuine lead additive and cannot be mixed with substitutes. If you have previously been using a lead substitute, run the tank down and refill using the correct concentration of TetraBOOST. Do not change back and forth, as this can seriously damage your engine.

13. What about the other ideas, such as in-tank or fuel line bolt-on solutions?
There are a number of seemingly magic solutions that would appear to enable your engine to run on unleaded fuel even though it may have soft valve seats, a high compression ratio, etc. These include lead pellets in the tank, the rearrangement of molecules in the fuel line, lead or tin pellets in a capsule for placing in the fuel line and so on. These products, along with the possibility of divine intervention, spoon-bending by Yuri Geller or having your car personally blessed by your local vicar, priest or rabbi, may indeed be considered by some to be of value. We have so far not seen any scientific basis to show that they work. Remember that TetraBOOST is based on science – not science fiction.


14. Can I use TetraBOOST in a car fitted with catalytic converter?
No. All cars fitted with catalytic converters are designed to run on unleaded fuel only.


15. Is TetraBOOST a tested solution?
Yes. Leaded fuel has been the de-facto standard for engine care for over 80 years. TetraBOOST makes genuine, authentic leaded fuel so it cannot be bettered in caring for your cherished motor cars. TetraBOOST was analysed and approved by the FBHVC (Federation of British Historic Vehicle Clubs) in 2001. Our product has been extensively tested and dyno’d, and has proven to be totally effective at stopping any signs of valve seat recession. TetraBOOST has now been used on the track since the year 2000 and the results speak for themsleves.


16. Does TetraBOOST ‘E’ Guard 15 provide other protection?
As well as stopping valve seat recession which has already proved to be a very real problem, lead lubricates valve stems and guides and some say it leaves an anti-corrosion film on cylinder bores – essential when cars are laid up for long periods. In addition, our new anti ethanol chemistry protects cars and motorcycles both when in use, or when stored over winter when water absorbtion is at its worst.


17. Can I put new valve seats in my old car and just use unleaded?
In certain cases, yes.  However many multi-cylinder cars can prove very expensive to convert and some engines are not capable of being converted in this way.  Problems with fitting hardened or stainless steel valve seats include:

  • Drilling into the waterways of old but still sound blocks and heads.
  • Cracked heads due to differential expansion of two incompatible metals with different expansion rates.

TetraBOOST is able to provide an economical and totally reliable solution to these disastrous problems.


18. Can I find leaded fuel on the continent?
No. There is no leaded fuel in Europe. TetraBOOST is the only solution to long distance touring or classic rally requirements in the UK, Europe and beyond, including several cars on the Peking – Paris rally.


19. Can I race with TetraBOOST?
You most certainly can. TetraBOOST is suitable for any high speed use and is considerably cheaper that the 5 star fuel offered at race circuits. It is also more effective than many of the specialist race fuels available by the drum. A great many people race and hill climb on TetraBOOST with great success.

As TetraBOOST was FBHVC approved some years ago, it may be used in any class of racing where:

  • Fuel choice is free.
  • Only approved additives are allowed.
  • BS 4040 leaded fuel is allowed.

TetraBOOST is capable of raising the octane up to 106 for specialist race engines. TetraBOOST recommends Shell V-Power for high octane mixes for race use. Typical dyno results show a 3-4% increase in torque over unleaded/AVGAS mixes with a 2-3% increase in BHP.


20. Is tetraethyl lead dangerous?
Tetraethyl lead in its raw form is highly toxic. TetraBOOST contains tetraethyl lead in solution, in which form it can be safely handled if used in accordance with the instructions.


21. If I get TetraBOOST on my hands, what must I do?
Wash your hands immediately in soapy water, or paraffin. When pouring TetraBOOST, use rubber gloves and wear eye protection. Similar preparations to TetraBOOST have been used at race circuits abroad for years without problems. Wipe spills off paintwork and handle all fuelling out of doors. This is a sensible precaution whatever fuel you use.


22. Is TetraBOOST legal?
Yes. TetraBOOST is a genuine lead additive, so it falls outside the European Union legislation on leaded fuels. It is sold with fuel tax and duty paid.

23. Can I purchase TetraBOOST from outside the United Kingdom?
As TetraBOOST is a volatile liquid, no facilities currently exist for worldwide distribution. TetraBOOST can, however, be delivered in some parts of Europe. Call for details


24. What is the shelf life of TetraBOOST?
TetraBOOST ‘E’ Guard 15 is now supplied in cans which have been tested with the base solution of aromatic hydrocarbons for up to 3 years and have shown no deterioration of can or product. TEL (tetraethyl lead) is, however, susceptible to oxidation in daylight. So containers should be stored in a cool, dark place. Mixed fuel should only be stored in metal or approved red plastic fuel containers.


25. Who uses TetraBOOST?
TetraBOOST is used in all manner of classic and collectors cars, from veteran, Edwardian, vintage and post vintage, through to all the post war classics. It is used extensively by the racing fraternity, powering cars from blown Austin 7s to V16 BRMs. Our product is used by National and International Motor Museums in cars and bikes and by acknowledged marque experts and renowned restorers.


26. Is TetraBOOST accepted by the race authorities?
TetraBOOST can be mixed in various concentrations to conform to MSA regulations – (section P) BS4040 leaded fuel – providing RON values from 97 to 101 and giving a lead content from 51mg to 150mg per litre. The standard dose provides a two point octane increase. When used with Shell V-Power 99 unleaded, it makes real 101 octane leaded fuel, which compares fully with well known brands of trackside sourced race fuel available in drums. Where regulations permit, TetraBOOST mixes up to 106 RON. See our dosage chart for full details.

Only TetraBOOST fuel additive provides the unique flame front control of tetraethyl lead, preventing pinking and high speed knock, with improved combustion, smoother pick up, better throttle response and cooler running – proving its value even in cars fitted with unleaded conversions. Typical dyno figures show 2-3% increase in BHP and 3-4% increase in torque over other fuels, including AVGAS mixes. TetraBOOST is becoming the choice of serious competitors and their engine builders.


27. My car has hardened valve seats – can I still use TetraBOOST?
Yes. TetraBOOST ‘E’ Guard 15 not only protects valve seats, but also valve stems and guides – often still vulnerable after valve seats have been replaced. Remember that TetraBOOST also acts as an octane booster in its own right, which many cars require. Of course, it also protects against the acid which causes corrosion of the fuel system and rots and corrodes many fuel line components.


28. What if my car was built before leaded fuel was available?
Despite your car being built before leaded fuel, it will still run better and last longer on leaded fuel. Counter-intuitively, older, long-stroke engines run better on higher octane fuels because the flame front propagates at a more controlled rate. This gives smoother combustion over a longer proportion of the power stroke.


29. What about lead memory?
Sadly, lead memory is not to be relied upon. When you think of the action of the valves, which open and shut and rotate slightly hundreds of times every minute, a thin lead coating on the valve and seat will not last further than round the block! On some old engines a degree of valve-induced case hardening may alleviate VSR, but this cannot be relied upon.