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Discussion Starter · #1 ·
Hi Guys

Think I know what the answer is to this but need to check it out.

Went to the petrol station to try SU but they only had LRP.

Is there a difference between SU and LRP, presume there is, but what is it?? Cheers :)

wrinx
 
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Discussion Starter · #2 ·
Hi Wrinx,

As far as I know LRP is just a slightly different version of std unleaded so is a lower octane than SU (super unleaded) which should be about 97/98 RON (shell optimax is a new version of SU)

Cheers,
Alex
 
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Discussion Starter · #3 ·
LRP as you will know, is the replacement for 4 star, so old cars without cats can still run without expensive additives.
LRP has a higher Octane rating than Unleaded (just like 4 star did), but the stuff they put in it (can't remember the name) will be harmful to your cat. !!!!

Hope this helps

Marlon
 

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189 Posts
LRP is 4 star with no lead.

Cats are damaged by lead.

Why not use LRP with a cat?

:confused: :confused: :confused:

jimybob - please tell us why
 
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Discussion Starter · #6 ·
Had a look around the net etc. There is conflicting information about LRP and Unleaded. The fuel companies DO NOT recommend the use of LRP in cars with catalytic converters. The additive in LRP is potassium. I'm not sure if a different additive is used in Unleaded. The potassium maybe reacts with the cat ????
Another point is......LRP does not have to conform to any standards, so you might be putting crap in your tank.
Potassium (sodium can be used) has an affinity to water, which means there is a chance the fuel can become contaminated with water (by absorption from atmosphere etc.) more easily.

Here's a bit from Texacos site:

Texaco Lead Replacement Petrol (LRP)

Texaco LRP was introduced for use in petrol (spark Ignition) engined vehicles as a direct replacement for the now obsolete, 4* Leaded Petrol.
Texaco LRP has the same octane as the (now obsolete) 4* leaded grade and so no alterations to the ignition setting should be required. In addition LRP contains potassium based anti wear additive to help protect the engine from exhaust valve/seat wear.
LRP is recommended for use in vehicles which previously used 4* Leaded Petrol but is not recommended for vehicles fitted with a catalytic converter nor for continuous use in vehicles used for racing, towing or driving at high speeds for long periods of time.
In cases where such driving styles are required the vehicle manufacturer should be consulted as to a longer-term remedy, such as having hardened valve/seats fitted.
Texaco Lead Replacement Petrol contains a detergent additive to help keep carburettors, fuel injectors and inlet valves clean, maintaining driveability and performance.

Still no clear answers, but I would steer clear of LRP in modern engines.....just to be safe.

Marlon
 
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Discussion Starter · #8 ·
Hi Guys
Usually the end of the pistol for LRP has a bigger diameter than Unleaded pistols to prevent people mixing up what they put into their cars. I have seen this all over but it’s some time ago I was in the UK last time. :rolleyes:
Cheers
Erik
 
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Discussion Starter · #9 ·
yeh the pump nozzel should be a different size.
the addative used in LRP damages the platinum coating thats inside the CAT.
 
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Discussion Starter · #10 ·
Don't know if this is useful to you, but they still sell Super unleaded at a few garages where i live, have filled up my 155 with it for about a month and only difference really is the mpg is slightly improved. Say from 30 or so upto 34 MPG

Didn't notice much difference in performace, but it did make the engine run smoother!!
 
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