5 replies to this topic

[gonzo2053]

its a 1986 mini city E, woman said it used to take 4 start ( but she couldnt find it so started using unleaded,) is this safe for the car??? i have a tesco petrol station that still does 4 *** so should i use 4*** or unleaded and is it ok to mix them if i try and change back to 4*** ???

[thorpey]

wont hurt to mix them for sure,ive run all my minis on unleaded prob not the right thing to do but the lrp is not up to the same standards as the old 4star anyway so i figure your better off using whats more readily available and better quality and cheaper,try using super unleaded like optimax and the like it seems to work fine in mine.

[Dan]

Super unleaded is even more corrosive than regular unleaded! The octane number isn't so important for the health of the engine as the additive provided you re-time it a bit. Pre-injection A series can run safely even on two star, but the leaded ones need the lead or something similar to protect the head. Believe me, I had a head which became un-usable inside two years due to valve seat recession. It had unleaded seats but standard valves for some cheapskate machine shop reason and it just wore out.
You will get away with using LRP or an additive in unleaded every four to five refuelings. You can also still buy real four star if you know where to look. But the best thing is probably to keep a bottle of additive in your boot and add some every time. There is now an additive available which contains real lead.
Oh and at the moment, since it has been running on unleaded for a while it will have no lead memory so you best get some additive in it quick.
In the longer term, you will need the head converted which is relatively cheap so long as you go to a good engineer!

[gonzo2053]

so your saying if i keep on using unleaded i should use an lead additive to the petrol....? or i could just keep on jusing 4star and not have to bother

[Guess-Works.com]

As Dan says... go the additive route... I use Castrol Valvemaster Plus ( This has an added octane booster aswell ) but there is a Non "plus" version aswell... which just does th elead replacement ( and is a little cheaper )

Cost 10 quid from Halfords andis good for 200ltrs of petrol ( adds 5p to a Litre in real realterms, )

But is 100 times better than LRP which IMO quite frankly is not worth spit, as it is not controlled or regulated by even as much as a British Standard.

The alternative is an unleaded head ( or getting new seats put in you existing head )

or..

There are a few garages across the country where you can still get 100% leaded 4 Star.. follw the link to a forecourt near you...

www.leadedpetrol.co.uk

[philster]

if you're putting unleaded in don't use supermarket or petrol from small outlets, Only use the big names like esso, bp, shell, texaco. All the big petrol companies have their own inspectors who will test a batch of petrol before it is used. It is tested not only for octane rating (ie minimum 95 for unleaded and a minimum 97 for super) but also for what they call calorific value. Now i don't know that much about the calorific value of petrol but basically its a measure of how good the petrol is before any detergents or additives are added.
Supermarkets and the smaller outlets just ring up the petrol companies like for instance shell, and they will send them some say 95 octane petrol. This is however not the best petrol they have as this is saved for themselves ( for optimax and stuff like that). Independant tests that have been carried out found that some 95 octane pertol was as low as 90 from some garages which is not good at all.