Thanks for that D- that looks like it may well be a goer for the 1200.
Cheers
Dave

A thicker oil does help with older engines no doubt yet I found
by 3 fills of Mobil 1 on a low km suzuki gti engine it became noisier
yet revved freer than the hpr30 however I tried HPR5 and by the
second fill the engine ran very quiet and revved just as nicely.
HPR5 is full synth but also full zinc and 60% cheaper than Mobil 1
http://www.supercheapauto.com.au/onli ... pid=14911#Recommendations

On 2 stroke race bikes there used to be a debate about the heavier oil adding ring seal leading to more power.

On the 1200 I use a heavier oil because the few extra ponies is not worth the risk to the lifters as mentioned.

I used Motul in the Showroom Stock Miata, one of the most noticeable things was the mileage increased nearly 2 mpg (in street driving) so I would think the horsepower increased as well.

Tom

Yes, thats exactly the same issue that I have had in days gone by.
Franklins in Auckland who did my latest cam were adamant -use an oil with zinc in it as the modern oils are causing excessive cam/ follower wear on older engines.
So unfortunatley the synthetic looks a no go.
Cheers
Dave

I use HPR 50 in the A12 in the race car. 40w60. I just warm it up before I give it a hard time. It would be costing some power, but I've had cam and follower wear issues in the past.

HPR30 is for older engines totally different viscosity flow rate
more suited to engines with older seals to prevent leaking as well
HPR 5 is closer @ 5w-40

Thanks so much Simon,question answered!
Cheers
Dave

Just finished doing the test between two oils

HPR30 20w50 Mineral w Zinc additives. 124Kw and 202Nm
Mobil 1 0w40 full synthetic 127Kw and 205Nm

Both at 75c oil temp. It would have been better if the oil temps were up around 90c, but we were worried about running out of E85 waiting for the oil to get up there.

Thanks Simon and everybody else for the feedback.
Wow, the Mobil 1 0W-40 really is way out in front!
How would that sort of oil run in an A series engine? ( this is for a race car)
I'll be really interested to see what, if any improvements are to be had by moving to this sort of oil.
Cheers
Dave

Just photo copied a page from a book that talks about this some more. Dyno results with different oils etc. Hope it's readable.

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  viscosity and HP.jpg (195.87 KB)