Oil options, what's doable... Who uses 0W-40?

[Guybrush]

After snooping round my garage i've found the following oil
- Mobil 1 0W-40 Fully Synth
- Mobil Super S 10W-40 Semi Synth
- Halfords 5W-50 Full Synth "For track days and enthusiastic driving" :crap::laugh:
- Auto care 5W-30 Semi Synth


I'm thinking the Mobil 1 is too thin?
The Super S is probably the best choice for the c1j
The halfords muck will probably work ok
But what about the auto care stuff... good for using as "engine flush" oil ?

[R5MJH]

we use mobil 10/40 super 2000 semi syn

[Mr Raider]

Would not use engine flush itself, maybe just flush with cheap oil, then drop it after 100 miles and then use the usual semi synth 10w-40 or 15w-40. Probably not a good idea to use fully synthetic or really thin oil on an old pushroad c1j engine

[Guybrush]

Would not use engine flush itself, maybe just flush with cheap oil, then drop it after 100 miles and then use the usual semi synth 10w-40 or 15w-40. Probably not a good idea to use fully synthetic or really thin oil on an old pushroad c1j engine

yeah that canned "engine flush" stuff is :sad2:
i just meant using the 5w-30 for 100 miles before dumping and putting in the 10w-40.

i'm wondering why i bought the 0w-40 fully synth :cry:
no one using it on the c1j?

[Lowiepete]

Probably not a good idea to use fully synthetic or really thin oil on an old pushroad c1j engine
Could you please explain why?
Back in the day, it was Elf Competition Oil that was recommended. Wasn't that fully
synthetic? My local stealer has just sold me 5l of Elf Evolution SXR 5w40 for 19.71+vat.

Any reason I should not use it? Some while ago I was reading a study of how engine oils
resist high temperatures, or not. The Elf oil came out as one of the best, so I'm happy to
stick with it. If I shouldn't use it in the 5GTT, then I'll save it for the F4RT engine service
early next year...

Regards,
Steve

[Guybrush]

interesting article
http://www.rtoc.org/boards/showthread.php?t=4767

[Mr Raider]

Could you please explain why?
Back in the day, it was Elf Competition Oil that was recommended. Wasn't that fully
synthetic? My local stealer has just sold me 5l of Elf Evolution SXR 5w40 for 19.71+vat.

Any reason I should not use it? Some while ago I was reading a study of how engine oils
resist high temperatures, or not. The Elf oil came out as one of the best, so I'm happy to
stick with it. If I shouldn't use it in the 5GTT, then I'll save it for the F4RT engine service
early next year...

Regards,
Steve

When the gt turbo's came out, mineral oil was specified. Some motor factors/shops will still give you that if you give them the reg. Obviously you can run what you like, the origins of the c1j go back to around the 1950's so they all are old pushrod engines. Ive always used semi-synth in mine, have run mineral a couple of times, not a big boost engine, running 15 psi. Most people use 10w 40 or 15w 40 semi synthetic, some run fully synethetic. To be fair I think the modern oils are long life so fully synthetic, modern engines have tighter tolerances that what the c1j does. I wasnt aware Elf competition oil was fully synthetic, in fact ive just bought some Elf Evolution SXR 5w40 for my daily a 172 clio, £28.00 delivered you cant go wrong! ;)

[DaveL485]

Does anyone understand what the numbers mean? Thats important. Google it.


Fully Synth 5w50 is what I use, have used for years and will continue to use on all my 20th Century Renault engines.


Synthetic because

http://www.kewengineering.co.uk/Auto_oils/images/fig_4_synthetic_vs_mineral_oil.jpg

5w for good cold start lubrication
50 for keeping the viscosity up, and therefore oil pressure, when i'm hammering the **** out of it :)

The 172 gets 5w30 as it's a more modern, lower tolerance engine and the cooling system is better.

[casper]

Does anyone understand what the numbers mean? Thats important. Google it.


Fully Synth 5w50 is what I use, have used for years and will continue to use on all my 20th Century Renault engines.


Synthetic because

http://www.kewengineering.co.uk/Auto_oils/images/fig_4_synthetic_vs_mineral_oil.jpg

5w for good cold start lubrication
50 for ke:confused:eping the viscosity up, and therefore oil pressure, when i'm hammering the **** out of it :)

The 172 gets 5w30 as it's a more modern, lower tolerance engine and the cooling system is better.

I use mobil super 10/40 semi synth.Is this oil not ideal then?

[DaveL485]

I use mobil super 10/40 semi synth.Is this oil not ideal then?

The 10w means it's thicker when cold and it'll take longer to get into all the places it needs to be (Though the difference won't be huge).

The 40 means it'll be thinner, when hotter. A sixties designed, twenty plus year old pushrod lump ain't gonna love thin oil.

15w50 feels about right to me.

This is IMO, obviously, but I did study Materials Science at Uni so (i like to think) I have a fair understanding of the science, and have owned Turbo Renault's continuously since 1996...plenty of experience (most of it hard earned lol)

[Brigsy]

I would agree with that dave. I tend to go for 10/60 fully synth on a tuned c1j to keep the oil pressure in check when hot. 10/40 is OK for a standard lump.

[TNT ANDY]

http://www.zag.si/~jank/public/bmw/oil_bible.pdf

Oil bible

[newbstar*]

0w40 is fine on a c1j depending on the condition of it!