Hi, paul H. iv'e only used this with forecourt diesel and i can tell its working after about a mile or so after the first fill, well thats how long it takes from tank to pump etc. i would recomend running your tank down low first to maintain the correct mix. i then carry a small bottle with 125ml in
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remove the fuel cap, tip the oil in first then put 25 litres of diesel on top. if there is a down side, it's due to the reduction in engine noise and then you can here squeaks and rattles you've never heard before. thats the only down side ive found in 4 years
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