Thread: Mixing engine oils?

Fully synthetic is more resistant to thermal breakdown in the turbo... the only good way to prolonge the engine's life without changing the oil twice a year IMO, especially in warm regions.

Originally Posted by rangieman

X2 No .
Oh a Simple Google got this for you
What Happens if You Mix Regular and Synthetic Oil?

You an your google . LOL.
Here's another ,list of 20 top search engines. just in case
https://www.reliablesoft.net/top-10-...-in-the-world/

I am not well versed in this area but when I spoke to the guys at Penrite after accidentally mixing 2 different viscosity Penrite oils their primary concern was the matching of the additive package, if they were matched and both oils were within tolerance of the engine specs it will be ok.
My take home message = doable if needed but wouldn't do it intentionally and would change at a shorter interval if I did. As for semi and synthetic, the smart money seems to unanimously vote a big no no but it's your ship steer it as you see fit.

Originally Posted by thai_tiger

value for money and high quality product, I couldn't top it.
DELVAC 1 ESP 5W-40

Has given poor results in cam and injector lobe wear in a TD5...

Penrite Semi-syn has proven a much better oil in a TD5 for reduced wear..

Originally Posted by Tombie

Has given poor results in cam and injector lobe wear in a TD5...

Penrite Semi-syn has proven a much better oil in a TD5 for reduced wear..

I know Tombie likes to play his cards close to his chest - or maybe he just likes to use the smallest number of words to get the job done - both are admirable traits - anyway, this valuable information is definitely based upon objective measurements provided by an AULRO member, whose posts I cant be bothered to track down :/
On that basis, I'm sticking with the Penrite Semi-Syn (Penrite HPR-5 Diesel 5W40) and I chuck in a bottle of STP too, since it's the ZDDP that makes the Penrite work properly in the first place. I know that you can actually have too much of a good thing, but I reckon that 443ml in 8 litres is ok.
Bohica, the Penrite is available at Repco in Millers Rd at around $80 when it's on sale. I've got 10L you can borrow till then, if you like. (STP is at SCA in Yarraville)

[QUOTE=Tombie;2586169]Has given poor results in cam and injector lobe wear in a TD5...





can you show your reference for that comment.

HPR DIESEL 5 5W-40 (Semi Syn.

Typical Data

Density at 15degC, kg/L0.859
Viscosity, Kinematic, cSt
at 40degC 100
at 100degC 14.7
Viscosity Index152
Cold Cranking Viscosity, cP at -30 deg C5576Zinc,
Mass %0.122
Phosphorus, Mass %0.110
Sulphated Ash,mass %1.34
Base Number10.7


Penrite also recommend their engine flush before changing your oil.

If that Penrite semi is proven good i'm sure that if there is some Penrite fully synth on the market that would be even better ... all the qualities shown in the data sheet will be lost due to thermal breakdown at any oil but the fully synthetic will keep them longer... i have a Lubricheck oil tester device and checked the oil many times on mine(i'm using only fully synth) and other's who are using semi or mineral and the difference is huge after the aprox same kms made....while the fully was still below 50% wear the others were on the orange or even red zone... i'm changing the oil based on that lubricheck tool not kms cos i observed that it wears out different according to the driving conditions and load... in fact the ECT and EGT has the greatest impact

in a nutshell: IMO the proper spec fully synth is the best for any turbo engine