Well folks, this is where I came in! Probably like many people, I was concerned when the old leaded Super was replaced by Lead Replacement Petrol (LRP); I was concerned whether it would provide the necessary protection for valves etc that the previous lead additive did. Statements from the petrol companies that the new petrol would provide adequate protection against valve-seat recession "under all but extreme circumstances" somehow didn't seem overly reassuring! But, like most people, I continued to pull up at the same petrol pump I always had, and just went onto using the new fuel.

I own both a car and a motorbike that are pre-1986, and designed to run on the old Super. Neither get driven a great deal, and so it took a while to really notice the symptoms; and even then I didn't initially connect the problems to the new fuel. But then I began reading about other people's experiences - and problems - with LRP, and "the penny finally dropped"! I then began investigating this whole subject of petrol, and in particular, what this new LRP was all about.

The main problem, of course, was the removal of the lead. As detailed on the other pages, lead performed two main functions; it raised the octane rating, thereby eliminating "pinging" in today's high-compression engines, and secondly it provided protection against damage to the valves and valve-seats (VSR). When the lead was removed, the petrol companies had to find other additives that would perform these same functions. You will see below how they handled this, particularly in relation to the prevention of VSR.

Remembering that LRP is really Unleaded with additives, another question  that has been raised is of the safety to our health of running this fuel on a car not equiped with a catalytic converter. Remember that it has been claimed that the additives used, particularly to raise the octane rating, were more harmful to our health than lead! But you'll have to wait until you get to the page on what the Petrol Companies and NRMA have said to find out what the official line is on this!

Another important point to remember is that LRP is only a short-term product. No-one is saying exactly when LRP will be phased out, but most reports seem to indicate that by the beginning of 2005 (some people say it could be earlier than that), we will have to find our own answers to the problems of running older cars on Unleaded petrol.
ALL LRP IS NOT THE SAME
One of the surprising things to me, was that all LRP is not the same!
Different petrol companies use different additives.
And more than this, because there is a sharing of resources, the additives in each brand of petrol will often vary from one state to another. This is partly because in each state the major petrol companies often draw their supplies from a common source; so that, for example, in one state BP might draw it's supplies from the same refinery as Shell, while in another it might get supplies from Caltex.

HOW THEY DIFFER
The main difference, as I've said above, is in the additives they use to provide the octane boost and the protection against VSR.  There are two main additives used; one is a manganese based additive, the other is
phosphor
based. (There are others, but these are the main ones). I haven't been able to compile a list of what each petrol company uses in each state, but I have been told that in NSW (at least around the Sydney area) Caltex and Shell use manganese, while BP uses phosphor. In other states though, as I mentioned, it varies considerably. For example, in Victoria Caltex and BP use manganese, while in Western Australia I believe they both use phosphor. It is confusing! And even the technical reps at the petrol companies have sometimes given conflicting statements about what additive they use! To find out what a particular brand uses in your area, I suggest you contact the technical section of the petrol company. (Or just look at your spark plugs - see item below).

MANGANESE. Manganese-based additives have been the subject of much research and concern overseas. For example, I have read that manganese has been used in Canada for over 20 years, while in the U.S. it was banned until 1995! General research that I have read seems to indicate that it is not as dangerous to health as was suspected, although I was told by one petrol company technical representative that there was a suspicion that manganese could be linked to Parkinson's desease. This, they hastened to add, was not proven, but it was enough, so they said, to have them prefer phosphor, even where it was more expensive for them to do so.

PHOSPHOR. The main problem with phosphor seems to be that it doesn't burn as cleanly as manganese. This has resulted in problems with spark plugs sooting-up. Petrol companies that use manganese and those who use phosphor both agree on this; manganese burns more cleanly, and doesn't produce the same problems of fouling the plugs that has occurred with phosphor. One petrol company technical representative told me that this sooting effect had been such a problem in one particular state (I think it was Western Australia), that they changed to manganese, and the problems were solved.

THE PROBLEMS PEOPLE HAVE HAD
To be fair, I have to say that many people have just pulled up at the same pump they always have, and just gone onto the new fuel without noticing any differences at all. Some people have even told me that they didn't realise  they weren't using "Super"! Other people have created problems by trying to tune their engines by the colour of the spark plugs (see the item on spark plugs below). However for others, there have been problems.

I have already mentioned one problem that has been quite prevalent, particularly it would seem, in certain areas, and that is the sooting-up of spark plugs, resulting in poor running, mis-firing, hard starting etc.
Increased running temperature has been another commonly reported problem. Usually this doesn't show up on the temperature-gauge, but the motor does run noticeably hotter. This results in slightly rougher running, and sometimes harder starting when the motor is hot. One report I read in a motorcycle club newsletter claimed that this was sufficient to often result in greater "blueing" of chromed exhaust header-pipes. Apparantly large-capacity side-valve motors, with big cast-iron cylinder barrels are particularly prone to problems in this area. Rougher running, whether or not as a result of higher engine temperature, has also been a fairly common problem.

"Pinging" has also been reported by quite a number of people; leading one NRMA technical advisor to claim that he suspected that all LRP was not 96 octane-rating as the companies claim! Whether this is true or not would be hard to say, however the way the different petrol companies make their LRP does vary. For example, Caltex say that their LRP is based on normal Unleaded, while Shell claim that theirs is based on Premium Unleaded; although both list their LRP at 96 octane. (Caltex say they use an additive to boost the octane of the Unleaded they use, while Shell say they use a lower-octane version of their Premium Unleaded).

MY OWN EXPERIENCE WITH LRP
The first thing I noticed was a slightly rougher running, and slightly poorer performance of both the car (a 1974 Triumph 2500TC) and the bike (a 1984 Yamaha XJ600). But it was only fairly slight; there was no pinging, or mis-firing, no hard to start when hot etc. It felt like perhaps it just needed a tune-up, like the ignition was slightly retarded. And they were both a little rougher at idle than they had been. This poorer performance was most noticeable with the bike. Previously, a twist of the throttle would see it revving out quite willingly, but now it seemed a little sluggish, not as free-revving as it normally had been. But because I don't use either on a day-to-day basis, it took a while for these symptoms to become apparent, and I didn't initially attribute it to the new petrol.

But there was another, more alarming effect that I have not seen reported elsewhere. After a reasonable distance, around 50 - 60 km, both car and bike seemed to get hot and fumey. I have a bad sense of smell, so I wasn't able to identify any particular smell, but the effect was strong enough to make me feel a bit sick. My wife, who has a much keener sense of smell, complained when she was in the car that it "stinks of petrol"! This was making her feel ill after only a short distance in the car. I went looking for petrol leaks, but as it was also happening with the bike, and as I had read of increased running temperatures with LRP I became suspicious. The cause was proven to be the petrol (see the next section "What Are The Alternatives?"). I am guessing, but I think the reason for this may have had something to do with the anti-pollution equipment (or lack thereof). The car was built just before ADR27A, and so missed out on the anti-pollution equipment that came with that. Part of the requirements of ADR27A was intended to reduce emissions from unburnt fuel, and other evaporative emissions. Similarly, the bike does not have this sort of equipment either (ADR27A applied only to cars, not motorbikes). So I am guessing that in these vehicles, there is more emissions from unburnt fuel etc. and this could be the reason for the smell or fumes.

While, as I mentioned, there was no indication from the temperature gauge that the car was running hotter, I noticed particularly with the car that there was an abnormal amount of heat coming from around the engine even after it had been parked for some time.

I should mention that the LRP that I have mostly been using has been Caltex (with manganese).
THE EFFECT ON SPARK PLUGS
Back when we had leaded Super, the colour of the spark plugs were a good help when tuning the engine. (That was back in the days when fuel mixture was adjusted with a screwdriver not a computer!). The picture at left shows a plug from an engine in normal state of tune. However, since the removal of lead, that has all changed. Unleaded petrol normally leaves a black deposit on the plugs. We have had an unleaded car for our family car since 1990, and I can say that unleaded burns cleaner, and the plugs last longer, than was the case with the cars running Super, and that is something I like! But don't try to tune your engine by the colour of the plugs now!

HOW IT CHANGES
The plug pictured at left was from my car when it was running Super. (I had it stored in it's little box in the boot as a spare). It had probably done about 10,000km before being replaced in the course of routine maintenance. Yes, it looks like it might have been running just a bit lean at the time; although is still a fairly normal looking plug.



The plug pictured here is from the same car after running LRP for about 6 months. The rusty - orange colour is typical of what happens with LRP, and is a result of the manganese. Now, apart from just looking like it's been lying at the bottom of a fish-tank, this isn't actually a problem; it's just an effect!

If you use a phosphor-based LRP, I'm told the plug will burn black, just as with normal unleaded. Although, from what has been said above, you could find that it may be more sooty.
Click on the old car again to go to the next page, "What Are The Alternatives?" Yes, there are alternatives to using the LRP that the petrol companies have been serving us.  And, as you might have guessed from what you read above, I am using one of those alternatives! Maybe you will decide to go that way too!
Main Page
THE PROBLEMS WITH LRP