My sister in law drives an old Renault that takes 4 star petrol.
Now I once heard that you can still put unleaded in a 4 star petrol car... is this true?

Also is Lead Replacement Petrol created for cars that still take 4 star? Does anyone know where in sheffield it's sold?

Any help appreciated, thanks.

dont know about lesd free but here is a list i found by doing a google hope this helps m8 http://www.leadedpetrol.co.uk/southyorkshire.htm

Cheers for that Steevie/d.
Just called them and they've now closed for the evening.

They do have stock and will be back open in the morning at 8.30am.
Shame I dont know if her car can take unleaded or LRP petrol.

Doh!

According to practical classics magazine the renault 4 was not made to run on unleaded fuel (as aren't most old cars)
However i have an old spitfire and the general advice and findings of people in the know is that the car will happily run on unleaded fuel,(with slight timing adjustments) they ran some tests on a car ran for several thousand miles on unleaded and found no evidence of valve seat recession (the lead in 4 star acts as a lubricant and stops the valves receding into the head)
They found that many old cars had lead "memory" ie because of the build up of lead over years of use they were still protected .

So it may be just a case of adjusting the timing (easy job) and it will be fine.

So the renault may run happily for quite a while on unleaded.......... but the alternative is to have the hardened valve seats fitted (permanent cure)

But i would recommend using a lead substitute,you add a little to the fuel tank when filling up, it's extra expense but will still probably work out cheaper than four star.

For the record i run my spitfire on unleaded with no effect on performance.

Just read a report on lrp....apparently it does more harm to the valve seats than unleaded petrol will...the advice given is to run on unleaded or super unleaded with an additive (valve master is recommended) and do nothing until you have too.

It also added if the car is not run at high revs for long periods it should be fine.

Isn't it to do with a catalytic convertor? If a car doesn't have one (old ones don't) then I don't think it can take unleaded. You can have then fitted though.

i run my old midget on unleade but the valve seats ahd to be "hardened". u can get an additive to add to unleaded that will make it usable in cars such as the renault.

Originally posted by t020
Isn't it to do with a catalytic convertor? If a car doesn't have one (old ones don't) then I don't think it can take unleaded. You can have then fitted though.

I know you don't know about these things and was genuinely asking a question, but that comment tickled me at this time of night. Catalytic convertors are there to reduce emmisions (I don't know the ins and outs for a more scientific explanation I am afraid)


Older cars will run perfectly well on unleaded, I use optimax (for the extra ron) and an additive on mine. You can just run on normal unleaded as someone suggest above if you have a knock? sensor to automatically adjust the timing or adjust it yourself to avoid pre-ignition (pinking)

As Deano says avoid LRP.

Originally posted by Skatiechik
I know you don't know about these things and was genuinely asking a question, but that comment tickled me at this time of night. Catalytic convertors are there to reduce emmisions (I don't know the ins and outs for a more scientific explanation I am afraid)


Older cars will run perfectly well on unleaded, I use optimax (for the extra ron) and an additive on mine. You can just run on normal unleaded as someone suggest above if you have a knock? sensor to automatically adjust the timing or adjust it yourself to avoid pre-ignition (pinking)

As Deano says avoid LRP.

Oh well, that's why I'm not a mechanic! I'll worry about the outer looks and leave the insides to the pros.

Just to back up what's been said already, LRP is rubbish and will shortly disapear anyway, 'fuel catalysts' (pellet things you put in your tank) are also highly questionable and your sister in law's Renault will very probably run fine for forever and a day on unleaded anyway.

The Bayford Thrust leaded petrol they sell at White Lane is great as it's the proper deal, but it is pricey. If you are concerned fill up there one in four times or use a good quality additive like Millers VSP.

Having hardened valve seats is of course the correct way to deal with the problem but the bill would be more than the value of the car :)

Originally posted by willman
i run my old midget on unleade but the valve seats ahd to be "hardened". u can get an additive to add to unleaded that will make it usable in cars such as the renault.

I have a Dolomite and a Herald that have the same predicament.

As someone posted, get an additive, best place I have found is Halfords, around about £10 and lasts for months.

If you do not, you will burn out your valves.

Agreed, forget LRP.

PM me if you want exact details, bottle is in the car and I am feeling lazy right now.