Well good people of the forum. My P38A was using rather alot of oil, a litre every 300 miles, I was using a 10W/40 semi synthetic. On the advice of the good people of this forum I am now using a 20W/50 and I wouldn't have believed it had I not seen it for myself, the oil consumption has now dropped to about a litre every thousand miles. I am staggered as I can't believe oil viscosity should have such a bearing on consumption.
ifloochies
Well-Known Member
It most certainly does make a difference to consumption and even leaks, especially around seals.
Its all down to the breakdown in viscosity of the oil as the engine gets up to operating temperature and beyond.
Its all down to the breakdown in viscosity of the oil as the engine gets up to operating temperature and beyond.
Tricky of York
Well-Known Member
Henry, with winter around the corner I was going to try a 10W/50. What do you think?
Henry_b
Think outside, no box required.
I realise this flat but it’s a massive improvement on what it was.
flat
Well-Known Member
undoubtedly, I merely meant it’s not fixed, just the inevitable is delayed
Please don’t say that.
I still can’t believe that 10W/40 seems to disappear but the 20W/50 is stays in. It’s like they two different engines. This revelation is not a surprise to you?
Henry_b
Think outside, no box required.
Being 20w50 is a heavier grade the fact it is staying in longer isn't really a surprise it is either leaking it or eating it, the old bus will get through 20w50 slower than 10w40 in any case.
That said mine didn't eat 10w40.
RV8 is meant to use a heavier grade from factory, 10w40 is more for emissions and fuel economy purposes..
I only put 10W/40 in because that’s what the manual said. Fuel economy. . . . . you’ve got to be joking?
Henry_b
Think outside, no box required.
Passed it’s MOT with new oil last week so the engine must be alright. Thanks Henry.
Henry_b
Think outside, no box required.
Do you have the HC and CO figures from the MOT?
flat
Well-Known Member
Its either burning it or it’s leaking out, either way heavier oil is just a temp fix (although that temp fix might last quite some time of it’s just a leak!)
I hadn’t noticed a leak but MOT tester said that it’s leaking between engine and gearbox so I’m thinking that it’s rear crankshaft main so that explains why no drops on drive. I’d prefer it not to leak but I can live with it. I prefer it leaking it rather than the alternative.
