fats_40 Posted February 13, 2009 Share Posted February 13, 2009 i own a p38 n reg with 116000 on the clock,i currently use 15w40 magnetic but am thinking its to thin for the milege,thinking about putting 20/50 into it any sugestions ta Quote Link to comment Share on other sites More sharing options...
fats_40 Posted February 13, 2009 Author Share Posted February 13, 2009 also thinking about cutting the cats out aswell,but hoe will this affect the ommisions on mot,cause i have a rumbling sound when i pull off .after that it sounds fine thanks Quote Link to comment Share on other sites More sharing options...
q-rover Posted February 13, 2009 Share Posted February 13, 2009 I use 5W-50 and change regulary. Quote Link to comment Share on other sites More sharing options...
SteveRK Posted February 13, 2009 Share Posted February 13, 2009 Without Cats some engines from the early nineties can just about pass the MOT as emission levels were reduced i believe for more modern cars. I couldn't comment on whether the Rover V8 falls into this category though. That said if you remove the Cats you will need to modify the engine management system and will be running a fixed mixture setting - this might be a problem as emissions will vary with engine/air temperatures and therefore it might be tricky to get the correct setting for when its at the MOT. Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted February 13, 2009 Share Posted February 13, 2009 Two issues: 1 - I doubt the P38 will pass emissions without cats. 2 - Removing the cats does not make it run open-loop, you're thinking of the lambda sensors. If they're before the cats you can remove them without affecting anything other than emissions, if they're after them then you're going to have to trick the ECU into ignoring them or thinking they're still there and remove them (which would probably lead to a less than optimum state of tune & MPG). Also, cats are not the crippling barrier to fire-breathing performance that people seem to think they are so quite frankly I wouldn't bother. Oh and 15W40 or 20W50 should be OK but the later V8's (I.E yours) were specced to run thinner oil as the oil pump was different to the early types. Quote Link to comment Share on other sites More sharing options...
orangemach5 Posted February 13, 2009 Share Posted February 13, 2009 The old mans 95 Softdash 3.9 has a complete sports exhaust system fitted with tub manifolds and decat y with lambda's. It will NOT go through emissions at the MOT. We have cheated and fitted dickie seats and so its classed as MPV and doesnt require a cat for that year . I always use 20/50. Quote Link to comment Share on other sites More sharing options...
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