Unleaded petrol in my Gti 8v ?

Vince Pepper · Post by **Vince Pepper** » Thu Oct 15, 2009 9:21 am

Was looking through the haynes manual today as I have a leak on the drivers side about half way along the car, I thought it was lhm at first and resigned myself to the fact that 10 years sitting idle is not good for metal hydraulic pipes and one or more had rusted through. On further inspection in the morning there is no oily patch or marks left on the drive, so concluded it may be petrol leaking, hence I looked up fuel pump and pipe positions in the Haynes book to narrow it down, there I stumbled on the " use leaded fuel in pre july 1990 cars" I have yet to run the car more than 300yards and have put 20 litres of unleaded in as it was totally empty.

Do I need to run it on lrp ?

Post by **Tim Leech** » Thu Oct 15, 2009 10:06 am

Hi Vince,
It should be ok on regular Unleaded, see how it goes, if its "pinks" maybe think about some additives, Ive ran all my petrol powered BXs on unleaded with no problems but find the 16v is much happier on super unleaded which is what Citroen stated.

Does anyone sell LRP anyway?

Dollywobbler · Post by **Dollywobbler** » Thu Oct 15, 2009 12:02 pm

Think LRP has all but disappeared. As Tim says, normal unleaded should be fine. My 16v seemed quick enough on 95RON!

LiverMatt · Post by **LiverMatt** » Thu Oct 15, 2009 12:18 pm

Very few forecourts stock LRP now, but you'll find most will stock additives to use in pre-unleaded cars, such as Shell Millenium (that's how they spell it!) or Redex Lead Replacement fuel additive. It's relatively cheap too. This stuff doesn't affect the octane rating, it's designed to protect valve seats & the like.

Matthew

Dollywobbler · Post by **Dollywobbler** » Thu Oct 15, 2009 1:10 pm

LiverMatt wrote:Very few forecourts stock LRP now, but you'll find most will stock additives to use in pre-unleaded cars, such as Shell Millenium (that's how they spell it!) or Redex Lead Replacement fuel additive. It's relatively cheap too. This stuff doesn't affect the octane rating, it's designed to protect valve seats & the like.

Matthew

Not entirely true. Some additives do boost the octane rating. I wouldn't bother with them though. If my 2CV doesn't need 'em, I reckon a BX should be ok.

LiverMatt · Post by **LiverMatt** » Thu Oct 15, 2009 1:22 pm

The two products I mentioned don't increase the octane rating at all, they will specifically state as much if they do. Generally, they're not worth it when you're going to be paying just 7p more per litre for (as an example) Shell's V-Power unleaded fuel, rated at 99 Research Octane No. Incidentally, some 2CV users do use lead additives as Citroen didn't actually alter the engine when they stated it suitable for use with PU-50.

Dollywobbler · Post by **Dollywobbler** » Thu Oct 15, 2009 4:25 pm

It's true - Citroen didn't change the engine, but then they didn't really have to. I've done 80k miles in mine on unleaded.

kiwi · Post by **kiwi** » Fri Oct 16, 2009 1:43 am

Just wanted to point this out

In New Zealand the highest grade of Fuel (note I said highest) until 2003 was 95 octane and has been unleaded since 1996 for that grade.

We run BXs even the valvers out here most of them are UK imports so the only modification is the timing retardation that you do in the UK to use the lower octane. Worked for the last 14 years and still the BX lives.

Should not be a problem for you either.

MULLEY · Post by **MULLEY** » Fri Oct 16, 2009 12:58 pm

Kiwi's story reminded me of the time my dad came over to the uk in his cx which had a cat fitted to it & required running on unleaded, probably 1989, & there were only a handful of petrol stations that stocked this new fuel

So whenever we went out, we had to have a map to hand to always go via one of these garages, you can imagine the hassle & panic of running on fumes a few times

How times have changed.

kiwi · Post by **kiwi** » Fri Oct 16, 2009 8:06 pm

Bit clearer on that mulley pre 1996 there was Leaded in the Higher 95 NZ grade and there is and was 91 octane which had been around a few years prior I cant give a date for that before my time out there. Only reason I remeber this is I was working for certain Oil Companys durig the 90s.

Unleaded in the UK was introduced in 1988 and was when 2 & 3 star was phased out.

I do remember the mid 90s prior to going to NZ being advised not to use Unleaded 95 in my car even though it could according to the guide use Unleaded and was one of the Super Unleaded customers. After going to NZ I pointed this out to the mechancis that if it can run on 95 leaded in NZ and can run super unleaded in the UK then it can run 95 Unleaded. They gave me some garbage that it would damage the engine, which basically said to me they did not know or understand.

Funny though here we are over 10 years on and the BX of the time with probably the exception of pre 1988 1400cc are still running on unleaded no problems.

Some people will argue that running on Super unleaded will improve performance well I challenge that from years of record keeping and note that if it does it certainly is not enough to justify the higher price. If the timing is set for super unleaded then you must use that grade if it is retarded then use 95 but there is little point putting super 98 in if it is. Maybe it does work if you have a smart computer that adjusts the timing to optimise your octane of fuel but we drive 1980s designed technology and that is not a feature.

Just a side not I would not run a BX on 91 unless it was all that was available and mixed in with at least half a tank. Yes it was done by accident and it pinked which was a sure sign it was not tuned to low octane fuel

Way2go · Post by **Way2go** » Sat Oct 17, 2009 1:14 am

kiwi wrote:Maybe it does work if you have a smart computer that adjusts the timing to optimise your octane of fuel but we drive 1980s designed technology and that is not a feature.

The computer was a fitment on the 80's Saab 9000's that I had on 'D' & 'F' plates but I suppose they are in a higher markey bracket than the BX. Seem to remember that it ran well on either but for the edge that the higher octane gave you it probably wasn't worth the premium especially as these cars had the HP turbo's.

jonathan_dyane · Post by **jonathan_dyane** » Sat Oct 17, 2009 8:48 pm

Way2go wrote:
kiwi wrote:Maybe it does work if you have a smart computer that adjusts the timing to optimise your octane of fuel but we drive 1980s designed technology and that is not a feature.
The computer was a fitment on the 80's Saab 9000's that I had on 'D' & 'F' plates but I suppose they are in a higher markey bracket than the BX. Seem to remember that it ran well on either but for the edge that the higher octane gave you it probably wasn't worth the premium especially as these cars had the HP turbo's.

It was called APC, and IIRC was a thing of joy which was basically a knock sensor which on encountering detonation would reduce boost to a less aggressive level so as to prevent damage. This permitted running on cheap grade petrol as well as protecting the engine generally, and allowing high boost levels to be used without fear of damage.

God, I always fancied an early 900 Turbo...

kiwi · Post by **kiwi** » Sun Oct 18, 2009 12:16 am

The plot thickens

As far as I was aware none of the BX range could use lower than 95 Octane. But I was just informed via email that the BX19TZI can use 91 unleaded in Aussie and New Zealand.

Vince Pepper · Post by **Vince Pepper** » Sun Oct 18, 2009 12:57 pm

Thanks for all your replies on this one, it seems to run fine on the unleaded just wanted to be sure. I think the haynes book is a good few years old anyway and lrp was still easilly available at the time of printing.