Hello everyone, we all know that the most expensive oil isn't always the best and especially not for classic cars. So, just which oil is the most suitable for the older Z cars. I know there was an article in a recent/current Practical Classics issue but was interested in what everyone was using and if anyone had any horror stories with "the wrong oil"

I'll start with a story, in the army we use an engine oil called OMD90. It is a good oil and it contains a small amount of some sort of detergent. My friend at work has a triumph TR4a on its second engine now because of "the wrong oil".

So from this I am keen to use the most suitable oil for the 70's mechanics in the old Z.

Any help and fact and opinions are welcomed!!

Thanks for everyones time.

Matt

Y'all just opened a can of worms! roflol

Please don't take it the wrong way, but...........this should be good!! !I did a search a few months ago and read so much I got tired of reading:stupid:and still could not find an answer to the original question - I guess it is kinda like describing the perfect women................

I posted this topic on a UK Z site and have had a few suggestions already. Namely Millers 20/50 classic and Valvoline 20W-50 racing synthetic oil so far. Anyone use either of these?

There are lots of discussion of this on many of the Z car forums, like Travel'n Man I also get tired of reading after awhile. Oil is kind of a personnel thing. Find one that works for you and go with, comes down to cost, previous experience, research and peace of mind.

I use Valvoline Vr-1 for the engine, after reading a few things I picked this and have stayed with it. Is it better? Who knows, but I feel comfortable running it and I am happy to pay the price.

You really did open a can of worms, you will never get 'the best oil' you will only get the best oil for that person that replies. You can also use UOA (Used Oil Analysis) and see which one is working better for your engine after a few changes, too much hassle and dollars for me.

Thanks for that. Like you say, I am after an oil that's suitable rather than the best as "best" is as you say a personal preference. I read in this magazine article about the frothing of modern oils and how that can adversly affect the take up in a classic engines sump and oil pump. As long as someone else is running an oil without any dramas then i suppose it's suitable. It's a shame Nissan are trying to sweep the old days of datsun under the rug, otherwise they might be giving us the manufacturers recommended oils and lubricants like MG did.

Have you ever picked the wrong oil and had problems with your car?

The debate on which oil is best will always rage on. What is more important to realize is the older engines weren't designed to run some of the lighter weight oils on the market today, so would never run anything lighter than a 10W weight oil in our engines.

I'll offer the "nutshell" explanation I was given, not to start a war, but to offer a point of view by someone who did a lot of research on it:

Newer cars have a catalytic converter in the exhaust system which can get plugged up with the casual blow-by combustion of older oils, which contain Zinc. Older engines, due to the nature of their design, benefit from the added Zinc in the oil on those polished surfaces that are in constant rub/wear with other metal pieces (cam, crank, valve lifters, etc.). Newer engines have newer bearings, surface treatments and linkages in these areas that reduce the requirement for Zinc, and as such do not need Zinc in the oil. Oil manufacturers were pressured to remove the zinc from their motor oils.

Now, our cars without a catalytic converter and an older engine can use the Zinc in the oil.

From what I've been told, the oils to use (and this is not an all-inclusive list):

1) Valvoline Racing 10-30 in the Grey bottle

2) Shell Rotella Non-Emissions

3) Standard Dello Non-Emissions

All of these are a bit pricier than the standard convenience store quart, but they're "worth it".

I won't quibble the details, if your mileage on this issue differs, enjoy.

FWIW

E

yeah cool, that's kind of what I thought but just wanted confirmation. I know here in the UK and probably in the States as well, we have Castrol Classic, don't know how much it is but thought i might give it a go. I'll post the findings of 'Practical Classics magazine' here as well if anyone is interested. They tested a whole load of different oils in a load of scientific ways, which is probably why I switched off reading it in full haha. I'll read, digest and summarise it next week.

I likewise just recently read a lot of threads on oils until I got tired of it. I settled on Napa premium performance universal fleet plus 15w-40, it is also what my machinist recommended. This is Napa's best conventional oil and it cost $2.99, made by Valvoline for Napa. I started the engine on Joe Gibbs BR oil for the first 20 minutes. Then replaced this breakin oil with the Napa 15w-40 provided by the machinist. I have a Comp Cam street cam and I am using their additive to protect the cam.

My opinion is that the BEST oil has three primary characteristics:

1. It is clean

2. It has been in your car's engine less than six months

3. It is the appropriate viscosity for the current outside temperature.

(e.g. no 20W50 below 10 deg. C and no 5W30 above 40 deg. C)

Secondary characteristics, including ZDDP content are important, but less so that the three listed above.

I'll offer the "nutshell" explanation I was given, not to start a war, but to offer a point of view by someone who did a lot of research on it:

Newer cars have a catalytic converter in the exhaust system which can get plugged up with the casual blow-by combustion of older oils, which contain Zinc. Older engines, due to the nature of their design, benefit from the added Zinc in the oil on those polished surfaces that are in constant rub/wear with other metal pieces (cam, crank, valve lifters, etc.). Newer engines have newer bearings, surface treatments and linkages in these areas that reduce the requirement for Zinc, and as such do not need Zinc in the oil. Oil manufacturers were pressured to remove the zinc from their motor oils.

Now, our cars without a catalytic converter and an older engine can use the Zinc in the oil.

From what I've been told, the oils to use (and this is not an all-inclusive list):

1) Valvoline Racing 10-30 in the Grey bottle

2) Shell Rotella Non-Emissions

3) Standard Dello Non-Emissions

All of these are a bit pricier than the standard convenience store quart, but they're "worth it".

I won't quibble the details, if your mileage on this issue differs, enjoy.

FWIW

E

I second this explanation and reasoning. I live in Arizona so I use VR1 20W50 as it gets rather hot here in the summer. My only advise to you is once you choose an oil stick with it. Don't switch back and forth.

Jan