What about my question Jock. What do you think about using 10W50 oil on an used Punto engine?
Well Mike, I'm not a chemist which is what you need to be to give a really authoritative answer here, so I think all I can do is give you what has been my experience over the years? Thinking generally about engine oils I am of the opinion that a rough dividing line - as long as we are talking about "everyday" standard engines - is that if you have a direct injected and/or turbo charged engine lubricants become a "super critical" part of the equation. Turboed engines place unique and extreme demands on their oils and we seem now to be becoming aware that the oil formulation is playing a significant roll in carbon contamination of the inlet tract of direct injected engines, possibly more in normally aspirated than turboed as a turbo tends to "chase" the oil back up the valve stems whenever positive pressure is present in the inlet. Seat recommend a Castrol product for my little 3 cylinder 999cc direct injection turboed 95Hp Ibiza. It's awfully expensive so I looked up the exact Seat spec and then went to see if my favourite brand - Fuchs - did one that complied. They do and it's a worth while price saving! This may be of interest too:
https://www.fuchs.com/uk/en/products/product-program/automotive-lubricants/choosing-the-correct-oil/. Purely by chance you can see they've used the oil I use in the Panda and Punto as their label illustrated on the right. You can see the Fiat oil spec quoted at the bottom of their list on that label.
Perhaps reflecting too that now a days with VVT camshaft control and "stuff" like the twin and multiair engines - so an awful lot of modern engines - there are small fine filters in the supply lines to their operating solenoids which can be easily blocked by quite small pieces of debris. Frequent oil changes are of great benefit to many modern engines because of this and DON'T EXCEED MANUFACTURERS RECOMMENDED INTERVALS and in any event, even with, and perhaps,especially with, low annual mileage vehicles, where things like emulsification and fuel dilution of oil due to cold running becomes quite a problem, never go over the 12 months with your oil change. In my opinion these extended interval oil changes are not to be entertained!
However we are not talking about turboed or DI engines here but fairly basic port injected normally aspirated jobbies. I just looked up what is recommended for the 1992 Panda Parade (Felicity) we had for over 15 years. The recommendation was for a 15W/40 to API SG spec (I don't have an ACEA spec and in those days I only knew about the American Petroleum Institute spec system). In fact I ran her on Comma X-Flow 15W/40:
https://carsmart.shop/product/x-flo...&utm_source=adrac&utm_medium=cpc&utm_content= Which was my pal's budget range of oils at that time. It's only a basic mineral oil but the Panda's simple and unstressed engine thrived on it and was still running beautifully when she eventually succumbed to the dreaded tin worm. I also ran the one before on it which was a Panda 750 which was my daughter's first car. It too ran very well on it until the day it leaked all it's coolant away around Carlisle when she was attempting to drive to the south of England in it!
When we moved up to the 169 models I started using Comma X-Flow10W/40 (API SL - ACEA A3)
https://carsmart.shop/product/x-flo...&utm_source=adrac&utm_medium=cpc&utm_content= until my friend had to close his factoring business because of ill health. The factor I took up with then was selling a range of oils I'd never heard of but I was already buying Quantum oils from TPS for the VAG vehicles. At around that time it was Castrol who were the supplier of the Quantum branded oils to TPS and I suddenly learned that they, Quantum, had changed supplier to Fuchs. I'd heard of Fuchs - a very big German oil manufacturer - so I thought "If that's good enough for VW group, it'll do for me". On investigating further I saw that Fiat were now recommending an oil with a lower cold pour point 5W as opposed to 10w, so I looked for their equivalent which turned out to be their Titan GT1 5W-40:
https://www.ebay.co.uk/itm/Fuchs-Ti...i-BMW-VW-Mercedes-Porsche-Skoda-/132192978848 I've been using this in both our 8 valve 1.2 Panda and my boy's 8 valve VVT Punto for the last few years with no problems and the 5w cold rating seems to be good as I notice the valve clatter disappears very quickly when doing a cold start after not having been used for several days.
I'd be a bit wary of going under a 5w cold rated oil unless the manufacturer specifically specified it. I'm also a bit wary when manufacturers make big changes in oil spec, moving to "thinner" oils for older designs of engine still in use as I suspect it's often motivated by the ability to claim lower fuel consumption figures rather than ultimate engine life?
When, as you are here, thinking about the hot viscosity, which is where the 40 or 50 or whatever comes in, I think you need to think carefully about more than maybe the engine burning a little oil due to ring wear or because you are maybe trying to quieten a slightly knocking big end. The big problem with using a thicker than specified oil is that it, of course, is thicker - Doh! and the problem with this is that it's going to find it more difficult to get places. Now, if you've got a bit of ring wear then yes, this might be advantageous, but excess clearance on a big end isn't going to benefit really. The big, and rather obvious if you think about it, problem though is that everywhere else is going to be starved, to a greater or lesser degree. Don't forget a lot of engines use restrictors (put simply, small diameter jets in the supply drillings/pipes to certain parts of the engine) So the oil pump is going to find it more difficult to drag the oil up through the strainer mesh in the sump and then through all the small oilways to all the various parts of the engine. We know that by far the greatest time of wear in the engine is during those first few critical revs whilst there is little oil getting round the engine so why exacerbate this by using a thicker oil? (one of the reasons I was very happy to start using 5w in the newer cars) but, even when hot a thicker oil is not going to circulate so freely. Remember too that oil plays a much bigger roll in dispersing heat from components - especially the bottom of the piston crowns. Some engines, it's especially common in diesels, even have special spray jets which direct a constant stream of oil up the bottom of the piston for this very reason.
So, I think I'm saying, I would always use oil which had been produced to the manufacturer's spec - but, as you can see from the above, not necessarily the brand recommended by the manufacturer. Although I would use the manufacturer's recommended brand whilst still in warranty to avoid any arguments if a warranty claim came about. Consequently I think what I'm saying is that, in your situation I would be looking up my favourite Opie Oil Finder and going with one of their many recommended brands. If your engine has a definable problem, and many people prefer not to face this, or can't afford to face it, and I appreciate that - been there and got several T shirts - but you really need to fix the problem nott try to get round it by "fiddling" with lubricants. Oh, and by the way, if anyone is thinking about tipping a can of aftermarket "oil thickening gloop" into their old worn engine you would do well to reflect on what's just been said above.
As you can probably see I'm not a particular fan of additives in general - although they might have a part to play in a limited number of specific circumstance - However to bring a little more balance to the table, you might like to view the Oilem site:
https://www.oilem.com/ - click on help articles top right of page - which seems to be a blog linked to the Power Enhancer people. There's a lot of good reading in it. "Bob is the Oil Guy":
https://bobistheoilguy.com/ is another source of interesting reading if that is your "thing".
How'll that do? still awake Mike?
