gmsracing

Like the title says, I changed from Mobile 1 10-50 synthetic to Castrol 5-50 synthetic. With the Mobile 1, my oil pressure would always be 4.5-5 bar under load (or not) or high rpms. With the Castrol I noticed that under no load (boost) it runs at 4 bars but when I back off it runs at 4.5. I think it may be due to the lower viscocity rating. I'm also running it slightly higher than full on the dipstick now. (In prep for a track event.) Any comments?

alex_cristocea

I also changed oil today from mobil S 5w40 to castrol RS 10w60.The engine runs smoother and the oil presure on hot days with mobil was under 2 and with castrol it never droped under 3 bar.

smac951

I'm running dino oil. Will I get leaks with a switch to synthetic?

tjbreen

There is a lot of debate on this but my car (100% original with 80K at the time) did leak when I switched to synthetic. Next oil change I switched back to 20w-50 dino and was fine until I resealed the whole engine with fresh gaskets. I now run full synthetic with no worries and no leaks.

DFASTEST951

I'm still running mobil at the moment. Would like to change to AGIP but I have no issues with my oil dropping at all, ever. How many miles do you guys have on your motors? Could that be a reason?

alex_cristocea

170 000 KM

bearone

5/50's a big spread.

i run valvoline 20/50 synthetic and at operating temp see 4 bar at idle.

running over full can lead to cavitation which can be as destructive as the oil quantity too low.

87951

DFASTEST951

You know what, I've heard such good things about the Valvo Syn 20/50. I may try that next before going to AGIP

smac951

Mine has 71,000 and I'm going to switch to synthetic. What's AGIP?

DDP

I wouldn't run over the top oil marking. The oil level could be too high letting the crank contact the pooling oil creating air bubbles in the oil. Not a good thing-bubbled oil does not lubricate all that well.

2bridges

gmsracing - you will always show less oil pressure with a thinner oil. Nothing to worry about.
- don't get fooled into thinking the 5w oil is not lubricating as effectively, is simply thinner and flows easier.
if you run a 15-50 you would have seen the exact opposite.

Also - many folks run 1/2 qt over-full running X-cross or race events. No prob... although I would not go more than that over

HIGHBOOST

I read that having too wide a weight diff. ie:5W 50 can promote oil coking in the turbo

2bridges

I would find that highly unlikely with a full synthetic

wwinton

I am in Australia, a Porsche Workshop here that does a lot of race cars told me to run my 951 1 litre overful for track days.
He claimed they can starve for oil under high RPM cornering..

333pg333

Yes we run overfil on race days and stay well away from Mobil 1. It has been shown up many times including an independant test which I think Royal Purple won.