Is Mobil 0-40 OK, plus: how to rejuvenate plastics?

[Professorgearhead]

OK, I’ve been using Mobil 0-40 fully synthetic in the 'P' car for years. Can I use it in my Fulvia 1600 instead of the recommended 10-40? I assume it should be just fine because it has an even wider viscosity range, but thought I should check with you experts, just in case.

Also, what do people use to bring back some lustre to hard black plastic parts, such as dash panels, that have oxidized. There seems to be huge controversy over whether the product should, or should not, contain silicone.

[bernt]

OK, I’ve been using Mobil 0-40 fully synthetic in the 'P' car for years. Can I use it in my Fulvia 1600 instead of the recommended 10-40? I assume it should be just fine because it has an even wider viscosity range, but thought I should check with you experts, just in case.

If your engine has just been fully rebuilt, synthetic 0W40 will be fine. Switching to synthetic on a used, classic engine is not recommended for a number of reasons:

• the modern oils use detergents to keep dirt floating so it can be transported to the filter. But when switching to synthetic, the detergents will loosen the significant amounts of dirt that have been deposited inside of the engine. This will cause lots of wear in your engine
• old gaskets and seals can't always cope with the additives of modern synthetic oils
• if your main bearings and big ends aren't perfect any more, lower viscosity oils will cause a drop in oil pressure. 0W40 is very thin even at low temperatures

My engine has never been rebuilt, so I use cheap 20W50 designated for classic engines, and change more often.

Also, what do people use to bring back some lustre to hard black plastic parts, such as dash panels, that have oxidized. There seems to be huge controversy over whether the product should, or should not, contain silicone.

As you've already come across the controversy, I guess you don't really need more individual opinions. But still, here's mine:
I think it's more important to use a professional grade product, and not standard "supermarket" stuff. The standard stuff tends to give the surfaces a greasy look. The professional products usually separate cleaning and protection into separate products, so you'll have to buy more different bottles and pay more. But I think it's worth it. I like to avoid the silicone content, as my limited understanding of the chemistry says that it may help with "looks" but not "protection", but haven't dug any deeper into the subject.

Bernt

[Manxzag]

This topic came up a couple of days ago on the TR Register forum (Yes, Ive got a TR6)

The general advice was to try baby oil, would you believe!!!
It seems that the oil will soak into the plastic if left for a period and will not leave a super shine when polished off, and of course is gentle.

BTW The boss and I will be visiting Vancouver next month, if you fancy a beer and a chat PM me.

Nigel

[1,6 HF]

OK, I’ve been using Mobil 0-40 fully synthetic in the 'P' car for years. Can I use it in my Fulvia 1600 instead of the recommended 10-40? I assume it should be just fine because it has an even wider viscosity range, but thought I should check with you experts, just in case.
.

20-50 is generally recommended for the 1600. I've been running RedLine full-syn in that weight, though their 10-40 might also work. There is no problem with seals with the current generation of multi-ester synthetics.

[Fulvia-hf]

I believe 0W40 is way too thin for the Fulvia engine. The tolerances are not to modern standards and even after a fresh rebuild won't be. It is in the basic design. No problem just use thicker oil.
I use Motul 300V Competion in 15W50 weight. I use the Motorcycle variant 300V Factory line as that oil contains a dope for a wet clutch so I can use the same 60liter barrel for all of my classic cars and most of my Motorbikes. So far no oil related problems encountered. Just don't use 0W40 because you have it. Buy what is needed.

Cheers,
william

Fulvia HF 1200
Lada Niva 2121
Lotus Europa S1
Autobianchi A112 Abarth
Bimota SB2
Bimota YB9
Ducati 1000 SC
Honda VFR750RC24

[Professorgearhead]

Thanks for the advice!