An old question I'm sure

[Andy B]

I've read this (http://www.lotusbuzz.com/forums/showthread.php?t=110) and it would appear most of you are using fully synthetic oil in your cars but then most of you are driving cars with newer engines, 90 and up.
My Seven has a twin cam pulled from a 65 Lotus Cortina.
So far I've had 2 completely different views thrown at me, one from a guy that has raced and rebuilt many UK engines and another from a guy that owns and has owned many older UK cars.
View 1. Use Mobil 1 fully synthetic.

View 2. Use ether a diesel rated oil or add zinc dithiophosphate (ZDDP) like GM's EOS fortifier to my fossil oil, evidently something new API oils lack. This it is claimed prevents top end wear, cams, tappets etc.

Currently I use Castrol GTX 20-50 and my by the way my engine appears to "sweat" oil from every pore nothing super bad but my oil pan will never suffer rust perforation like 2 of my Japanese cars have.

Any advice would be greatly appreciated?

[WayneB]

I stopped using Mobil 1 when they took the ZDDP out of it.

They did it as the zinc was contaminating the catylitic converters on modern cars causing them to fail prematurely. most current engines with rollerised valvetrains have no problems using this oil (like my Buick) but flat tappet engines (like your twin-Cam and my 910 Turbo) suffer accelerated cam lobe wear when using this oil.

A racing engine builder I know had suffered two engine failures (camshaft lobes wiped off due to this.

Mobil 1 have apparently addressed this issue with a newer type of Mobil 1 (I can never find it though) Extended Performance gold cap and one packaged for for Harley Davidson Motorcycle engines(expensive).

I switched back to Valvoline 20-50 mineral racing oil in the Esprit BTW.

I am using Shell Rotella 10w-40 Diesel oil in the Oldsmobile 455 in my GMC motorhome (with no ill effects)

Most British Aeroplane and Motor produced aluminium castings are porus and sweat oil out, they are not high pressure castings (like on your japanese cars) using a 15w-50 oil makes it worse (as the oil is thinner when cold, so it leaks out faster when the car sits)

My Jaguar XJ12 leaks too (I put a tray under the engine like they used to in car dealerships)

[Andy B]

Thanks Wayne.
I found this on the Mobile site.
"Mobil 1 Extended Performance 15W-50 is formulated to provide outstanding engine protection for high performance engines and for consumers who want a higher viscosity oil and higher anti-wear performance ( ZDDP) than typically required by modern vehicles."
I think I'll switch to this, although I don't think I'll try the 15000 mile change interval.:001_unsure:

[Mark B.]

This doesn't apply to the UK Mobile 1 15W/50 does it?

[Autocross7]

Well, if you want know about oil there is some great info out there. Unfortunate enough... I see very little that relates to what and how you drive. For example, I hear a lot of folks say "hey, they use 'it' when racing"... okay. But is 'it' (oil, coolant, tires, etc) good for the street? sometimes yeas. Sometimes no. Race motors are often used once or twice and then rebuilt. Top fuel cars are awsome becuse they only have to run for a few seconds!

I prefer sythetic oils. The sheer stability is somewhat better and the flow seems a bit more 'even'. However, they do not last any longer really. The 'oil' might, but the addatives break down just like mineral oils. In the end, IMO, if you change your oil and filter on schedule or better, then mineral oil or sythetic oil is fine. Get what makes your car run and sound the best:yes:.

Cameron

[WayneB]

I dont know.

Mobil and some of the other oil manufacturers over here quietly dropped the ZDDP over here and the first we knew about it was all the camshaft and follower failures that started occuring in older cars (2 years ago).

I suspect one of the reasons it wasnt publicised was omiting it made the oil cheaper to produce.

As europe has pretty much now has the same vehicle Emmisions standards as North America, Im sure it would have been reformulated there as well.

Look for the Mobil 1 15w-50 branded as "extended performance", it has a gold cap here, apparently thats the good stuff for our cars.

Of course its more expensive than the "normal" Mobil 15w-50 and they dont sell it at Wal-Mart anymores (Asda in the UK).:(

[Autocross7]

As Mobile adds and in fact the bottles of the oil they make state that the oil in the bottles is good - as in unchanged for purpose - I expect Lotus owners could mount on heel of a law suit for failed parts.

Cameron

[bdboyle]

I've read this (http://www.lotusbuzz.com/forums/showthread.php?t=110) and it would appear most of you are using fully synthetic oil in your cars but then most of you are driving cars with newer engines, 90 and up.
My Seven has a twin cam pulled from a 65 Lotus Cortina.
So far I've had 2 completely different views thrown at me, one from a guy that has raced and rebuilt many UK engines and another from a guy that owns and has owned many older UK cars.
View 1. Use Mobil 1 fully synthetic.

View 2. Use ether a diesel rated oil or add zinc dithiophosphate (ZDDP) like GM's EOS fortifier to my fossil oil, evidently something new API oils lack. This it is claimed prevents top end wear, cams, tappets etc.

Currently I use Castrol GTX 20-50 and my by the way my engine appears to "sweat" oil from every pore nothing super bad but my oil pan will never suffer rust perforation like 2 of my Japanese cars have.

Any advice would be greatly appreciated?

After much searching and talking to a friend who spent 20+ years as a colleague at a Big Oil company research lab working in the engine lubes department...came up with:

Brad Penn 20W-50 Racing Oil (http://www.amref.com/bp_pb/7115_17_19_26_7150_BP_PENN-GRADE_1_Racing_Oils_PB.pdf). It's the old Kendall GT formulation, and, if the truth be told, has enough ZN and P to keep the flat tappet cams running just fine. Best part is that it costs as much as regular oil, and a lot of major accessory mfrs are on board with it.

Steve Veris over on the Europa mailing list formatted an extensive oil spreadsheet that was floating around somewhere...and that information (current as of a couple years ago, fwiw) is available here (http://www.lotus-europa.com/manuals/misc/engine/Oil_Info.htm).