Oil - 0w40 + 15w50?
Discussion
Not the standard oil question and please don't hit me too hard if the answer is obvious.
I have just bought mobil 1 0w40 for my Griff 500 but have decided from posts on here that Mobil 1 15w50 Motorsport would be a better choice.
As i don't want to waste the 0w40 can I get the 15w50 and then mix them, adding the same amount of each when I top up the car?
I have just bought mobil 1 0w40 for my Griff 500 but have decided from posts on here that Mobil 1 15w50 Motorsport would be a better choice.
As i don't want to waste the 0w40 can I get the 15w50 and then mix them, adding the same amount of each when I top up the car?
gerjo said:
Don't mix the two grades and stick to 10W40/15W50 or something, not thinner than that. A lot better for your engine.
Why? As I understand it most problems on the RV8 motors stem from marginal oiling on start-up. Surely a 0w oil will get round quicker than a 15w? Assuming the higher temp performance is equivalent it seems logical to me that the cold-start protection is beneficial
Mind you, I've completely worn out a 4oo lump in 45k miles so maybe I'm totally off beam
pupp said:
Don't mix the two grades and stick to 10W40/15W50 or something, not thinner than that. A lot better for your engine.
Why? As I understand it most problems on the RV8 motors stem from marginal oiling on start-up. Surely a 0w oil will get round quicker than a 15w? Assuming the higher temp performance is equivalent it seems logical to me that the cold-start protection is beneficial
Mind you, I've completely worn out a 4oo lump in 45k miles so maybe I'm totally off beam
I think it's because the major problems occur at higher temps, where a 0W is too thin. There has been a lenghty thread about the best oil for the RV8, where various experts give their opinion. (Semi)Synthetic 10W/15W-40/60 came out on top. It's also what e.g. V8Developments and Austec advise to use.
the pump, pressure valve and galleries were all designed to use the thicker oils available in the 50s 60s etc!
0-40, no matter how good it is, is just too thin! its fine for modern rice rockets and turbos etc, with modern tollerances and an oil system designed for it, but your old RV8 thumper needs a bit of body in its oil.
using a modern 10 15/50 will greatly reduce wear on start and very hot running and aid the longevity of your engine. frequent use, not allowing the engine to drain completely to the sump will also help. this could be why you hear of engines hitting 80+k miles without significant wear, yet you'll also hear of 30 even 20k miles engines needing cams etc. (BTW the cam is the last area to recieve oil as it is feed via lower splash and drop feed from cylinder cases above. no coincidence that these fail first!
a modern 10 15 oil will "cling" better than older oils due to additives etc ("magnetec" style) and as with everything quality is everything.
so why do modern cars like 0-40? rice rockets like all others go for power. the thinner the oil the less drag, the less drag the smaller the pump + less weight and drag = more power and better economy! this is what everyone wants provided the engine wear is controlled.
my oil pressure on my first engine used to drop to 6psi in the summer when hot! 6psi! and this was described as normal!!?? the cam went! new cam, adjustable relief valve and Mobil 1 motorsport later...25psi min and 20,ooo miles, most on track, and when the engine was inspected for sale it was beautifull! Thanks to Rich, Col and Jacko at Peninsula!
Nuff said
All IMHO, and experience!
0-40, no matter how good it is, is just too thin! its fine for modern rice rockets and turbos etc, with modern tollerances and an oil system designed for it, but your old RV8 thumper needs a bit of body in its oil.
using a modern 10 15/50 will greatly reduce wear on start and very hot running and aid the longevity of your engine. frequent use, not allowing the engine to drain completely to the sump will also help. this could be why you hear of engines hitting 80+k miles without significant wear, yet you'll also hear of 30 even 20k miles engines needing cams etc. (BTW the cam is the last area to recieve oil as it is feed via lower splash and drop feed from cylinder cases above. no coincidence that these fail first!
a modern 10 15 oil will "cling" better than older oils due to additives etc ("magnetec" style) and as with everything quality is everything.
so why do modern cars like 0-40? rice rockets like all others go for power. the thinner the oil the less drag, the less drag the smaller the pump + less weight and drag = more power and better economy! this is what everyone wants provided the engine wear is controlled.
my oil pressure on my first engine used to drop to 6psi in the summer when hot! 6psi! and this was described as normal!!?? the cam went! new cam, adjustable relief valve and Mobil 1 motorsport later...25psi min and 20,ooo miles, most on track, and when the engine was inspected for sale it was beautifull! Thanks to Rich, Col and Jacko at Peninsula!
Nuff said
All IMHO, and experience!
Guillotine said:
the pump, pressure valve and galleries were all designed to use the thicker oils available in the 50s 60s etc!
0-40, no matter how good it is, is just too thin! its fine for modern rice rockets and turbos etc, with modern tollerances and an oil system designed for it, but your old RV8 thumper needs a bit of body in its oil.
using a modern 10 15/50 will greatly reduce wear on start and very hot running and aid the longevity of your engine. frequent use, not allowing the engine to drain completely to the sump will also help. this could be why you hear of engines hitting 80+k miles without significant wear, yet you'll also hear of 30 even 20k miles engines needing cams etc. (BTW the cam is the last area to recieve oil as it is feed via lower splash and drop feed from cylinder cases above. no coincidence that these fail first!
a modern 10 15 oil will "cling" better than older oils due to additives etc ("magnetec" style) and as with everything quality is everything.
so why do modern cars like 0-40? rice rockets like all others go for power. the thinner the oil the less drag, the less drag the smaller the pump + less weight and drag = more power and better economy! this is what everyone wants provided the engine wear is controlled.
my oil pressure on my first engine used to drop to 6psi in the summer when hot! 6psi! and this was described as normal!!?? the cam went! new cam, adjustable relief valve and Mobil 1 motorsport later...25psi min and 20,ooo miles, most on track, and when the engine was inspected for sale it was beautifull! Thanks to Rich, Col and Jacko at Peninsula!
Nuff said
All IMHO, and experience!
Ok, thanks for all that... but doesn't the viscosity value indicate how the oil behaves at temperature extremes? ie a '0' will be more fluid than a '10' in the cold (and consequently flow and pump more readily), whereas two '40's should offer similar protection when hot (at the other end of the scale)? Surely oil pressure is just an indicator of resistance to flow... all things (ie bearing clearances) being equal, a lower pressure on one oil compared to another indicates it is flowing better, no?
well Robs the man,
if you want to change to new oil grade...drain refill.
good quality oil in, different make, different grade only available at the garage, and your low on oil? lets face it it aint gonna make cock all difference if you put 1L shell, esso, castrol, mobil etc in a 12L system. so long as its good quality, and you stick to synth or mineral.
good oil, not too thin (ie 0-40)changed regularly..thats it. Dealers are still putting in Mobil 1, but TVR only went to that due to a PW deal, which then went to Carlube...etc. all down to Money/sponsorship.
if you want to change to new oil grade...drain refill.
good quality oil in, different make, different grade only available at the garage, and your low on oil? lets face it it aint gonna make cock all difference if you put 1L shell, esso, castrol, mobil etc in a 12L system. so long as its good quality, and you stick to synth or mineral.
good oil, not too thin (ie 0-40)changed regularly..thats it. Dealers are still putting in Mobil 1, but TVR only went to that due to a PW deal, which then went to Carlube...etc. all down to Money/sponsorship.
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