Just been into Halfords or Halfrauds as I have learned to called it on this forum and they have some 5w-40 fully synthetic and 10w-40 semi for £12 for 4litres.

Might be handy for anyone looking to do a couple of oil changes to clean up their engine.

I'm hoping it's suitable, it says oil industry standards Area A3/B4 and API SM CF. Then it says recommended for applications requiring Mercedes MB 229.3, VW 502.00/505.00 and Renault RN0700/710

 

It's not with the other oils it'll probably be on a stand near the entrance..

They used to do a 5w-50 oil last year and called it track day, they don't seem to stock anything above 40 thickness anymore.

Fully synthetic is too thin for Zed engines, potential to promote oil leaks and reduces oil pressure in 25 year old engines, 10w-40 semi synthetic is the best option.

 

Jeff

How many litres does a Z engine take out of interest?

How many litres does a Z engine take out of interest?

 

Its around 3.5L for a Jap import and UK cars hold more. Just keep an eye on the dip stick when putting the last drips in.:)

3.4L with filter or 3.0 without, to be precise.

Its around 3.5L for a Jap import and UK cars hold more. Just keep an eye on the dip stick when putting the last drips in.:)

 

4 litres for my UK Spec. Used both Mobil 1 5w/40 and now 0w/40 fully synthetic without any problems.

Edited January 25, 20169 yr by AndrewG

Is fully synthetic 5w-40 thinner than 5w-30 part synth?? Isn't 5w-30 what Nissan says you should use?

Surely the numbers dictate the viscosity. So it's shouldn't matter whether it's synthetic or not.?

http://www.300zx.co.uk/forums/showthread.php?169792-The-Advantages-of-Synthetic-Oils-over-Mineral-oils

Is fully synthetic 5w-40 thinner than 5w-30 part synth?? Isn't 5w-30 what Nissan says you should use?

 

No - it's thicker mate. The second number is the oil's ability to withstand shearing at high temperatures - it's the "40" bit that counts at operating temperature. And a "40" grade is what Nissan recommended (as in 10w40 or 5w40). A "30" grade will be too thin once up to full temp!

 

The first number is the oil's ability to circulate from cold - the lower the number, the quicker it will get round the engine from start up until warm. In the UK, a "10w" will be just fine, as our winters are not severely cold.

Just been into Halfords or Halfrauds as I have learned to called it on this forum and they have some 5w-40 fully synthetic and 10w-40 semi for £12 for 4litres.

Might be handy for anyone looking to do a couple of oil changes to clean up their engine.

I'm hoping it's suitable, it says oil industry standards Area A3/B4 and API SM CF. Then it says recommended for applications requiring Mercedes MB 229.3, VW 502.00/505.00 and Renault RN0700/710

 

It's not with the other oils it'll probably be on a stand near the entrance..

 

Thanks for the heads up mate!

Yeh, I had some knowledge about the numbers, but I have read a few times people remarking about synthetic somehow being thinner than mineral based oils.. Doesn't seem to make any sense since the numbers dictate viscosity, like you say.

 

Like it isn't confusing enough no worries about the heads up.

Yeh, I had some knowledge about the numbers, but I have read a few times people remarking about synthetic somehow being thinner than mineral based oils.. Doesn't seem to make any sense since the numbers dictate viscosity, like you say.

 

Like it isn't confusing enough �� no worries about the heads up.

 

Your confusing viscosity with molecular size, fully synthetic will leak through gaps non synthetic will not.

 

Jeff

OK, so I've been advised to use 10W 40 fully synthetic in my 1990 TT.. Is this going to end up all over my driveway or not?

OK, so I've been advised to use 10W 40 fully synthetic in my 1990 TT.. Is this going to end up all over my driveway or not?

 

Depends on the condition of all of the engine seals and gaskets, not many original engine zeds with no oil leaks at all, 10W -40 semi is just fine and given that you should be thinking in the order of 4k miles to 5k miles oil changes then the prolongled service life that fully synth gives is of no consequence, 4k mile oil and filter changes are like money in the bank for your engine.

 

Jeff

I have 74,000 miles on the engine, no leaks at all except a very minor occasional drip from the rear crankshaft seal and when I say minor, I have only ever noticed it when the car has been on the four post lifts and there is a tiny amount of oil at the small square hole in the bell housing.

I've never found oil under the car on the floor and never seen any decrease in the oil level on the district along with zero smoke from the exhaust through turbo seals etc..

I've been putting 5W 30 fully synthetic in it as this was recommended by another mechanic source. So I'm guessing that my engine is in good shape and is tighter than a ducks backside across every seal?

I'm due an oil change shortly although I don't think I'll worry about the filter just yet as it had a K&N racing filter on the last oil change so I think it can handle another four thousand miles. But if I'm changing to 10/40 I guess the sensible thing would be to change it.

This seems to be a minefield of different opinions this subject, I've already been recommended several different oils..

I have 74,000 miles on the engine, no leaks at all except a very minor occasional drip from the rear crankshaft seal and when I say minor, I have only ever noticed it when the car has been on the four post lifts and there is a tiny amount of oil at the small square hole in the bell housing.

I've never found oil under the car on the floor and never seen any decrease in the oil level on the district along with zero smoke from the exhaust through turbo seals etc..

I've been putting 5W 30 fully synthetic in it as this was recommended by another mechanic source. So I'm guessing that my engine is in good shape and is tighter than a ducks backside across every seal?

I'm due an oil change shortly although I don't think I'll worry about the filter just yet as it had a K&N racing filter on the last oil change so I think it can handle another four thousand miles. But if I'm changing to 10/40 I guess the sensible thing would be to change it.

This seems to be a minefield of different opinions this subject, I've already been recommended several different oils..

 

Here here! I also put 5w-30 in mine with no leaks. It's not been driven though, just tick over for periods and revved a little when warm. Though all indications are I have a tight healthy engine also. I'll do a flush, filter change and change to the 5w-40 and hopefully all will be OK..

Oil preference is often a personal matter and asking advise or the opinion of others can help make a definitive decision but asking for advise or suggestions based on others handful of oil changes barely touches the surface of opinion, having personally done at least 1,000 oil changes on 300zx alone I feel strongly that fully synthetic is too expensive and not required for the average zed owner, especially given it should be drained out 4k miles later, and to one owner who suggested elsewhere he would do an oil change without changing the oil filter as it was not that old I despair??

 

Love the " no leaks at all except a very minor occasional drip from the rear crankshaft seal" comment, that means you do have an oil leak then, be it minor or not! and will only get worse over time, fully synthetic oil contains higher cleaning additives that can and do clean the engine out, however it also cleans out the passive bits of sludge that are keeping questionable seals from leaking, same happens when a zed been running plain water in the coolant system for years goes brown, clean it out and add antifreeze and wait for the leaks to start!

 

 

Jeff

I've been using Mobil 1 5w/40 fully synthetic sicne I got this Zed 4 years ago, I change it once a year with the filter, sometimes I've only done 1,000 miles, sometimes 2000, but not usually very much. I don't think it's that dear, £30 once a year compared to everything else I spend on the Zed is pennies.

 

Oil pressure looks to be the same as it was with semi synth 10w/40, I used to use that in my first Zed, the only difference was under hard driving it used oil, switched to fully synthetic on the first Zed and it stopped so that's why I've used fully synthetic since I got my second Zed.

 

I reckon I will go for Jeffs advice and try a 10w/40 semi synth this time, just to see if there is any differences.

Oil preference is often a personal matter and asking advise or the opinion of others can help make a definitive decision but asking for advise or suggestions based on others handful of oil changes barely touches the surface of opinion, having personally done at least 1,000 oil changes on 300zx alone I feel strongly that fully synthetic is too expensive and not required for the average zed owner, especially given it should be drained out 4k miles later, and to one owner who suggested elsewhere he would do an oil change without changing the oil filter as it was not that old I despair??

 

Love the " no leaks at all except a very minor occasional drip from the rear crankshaft seal" comment, that means you do have an oil leak then, be it minor or not! and will only get worse over time, fully synthetic oil contains higher cleaning additives that can and do clean the engine out, however it also cleans out the passive bits of sludge that are keeping questionable seals from leaking, same happens when a zed been running plain water in the coolant system for years goes brown, clean it out and add antifreeze and wait for the leaks to start!

 

 

Jeff

 

More confused than ever now. Gaz's link convinced me that fully synthetic was a no brainer and now I don't know what to go for... Can I go fully synth and then if a leak springs up change to semi and just put up with a bit of a leak until it bungs up? Wouldn't synthetic be the better option for maintaining good seals? Assuming they are good..

More confused than ever now. Gaz's link convinced me that fully synthetic was a no brainer and now I don't know what to go for... Can I go fully synth and then if a leak springs up change to semi and just put up with a bit of a leak until it bungs up? Wouldn't synthetic be the better option for maintaining good seals? Assuming they are good..

 

Its up to you mate I use the semi synthetic for my TT :)

Semi it is then... *phew* lol.

I don't do more than about 3-5K in mine per year. Each spring I treat it to a new genuine oil filter and some decent 10-40w semi synth. Works a treat.

Oil preference is often a personal matter and asking advise or the opinion of others can help make a definitive decision but asking for advise or suggestions based on others handful of oil changes barely touches the surface of opinion, having personally done at least 1,000 oil changes on 300zx alone I feel strongly that fully synthetic is too expensive and not required for the average zed owner, especially given it should be drained out 4k miles later, and to one owner who suggested elsewhere he would do an oil change without changing the oil filter as it was not that old I despair??

 

Love the " no leaks at all except a very minor occasional drip from the rear crankshaft seal" comment, that means you do have an oil leak then, be it minor or not! and will only get worse over time, fully synthetic oil contains higher cleaning additives that can and do clean the engine out, however it also cleans out the passive bits of sludge that are keeping questionable seals from leaking, same happens when a zed been running plain water in the coolant system for years goes brown, clean it out and add antifreeze and wait for the leaks to start!

 

 

Jeff

 

It means I do have the same oil leak as most Z's have as the rear crankshaft seal is well known for releasing a tiny drip even when they're virtually new seals.

Let's just put it this way, I put in 3.4 litres of oil over 3 months and 2000 miles ago. Driven daily and oil level has never changed, so I feel I can say the drip I very occasionally get from the bell housing inspection hole doesn't qualify as a leak as such, more of a sweat than a leak.

I'll be putting 10w 40 semi in next oil change though, get the best of both worlds...

Why would you change an oil filter every time you change the oil? An oil filter and particularly a K&N oil filter should be able to handle two oil changes minimum. I don't understand the "despair" comment?

You don't change an oil filter on every oil change, it's nit necessary. Today's modern filters are very capable of lasting two oil changes and I've owned cars in the past that have never had a filter change! One of which never so much as coughed in the 150,000 miles I drove it.

Had I said I would leave oil changes and filter changes for 20,000 miles then I could understand the over reaction of despair... Modern oils and modern filters are much more reliable and hard wearing than the good old days. If you're ragging the arse out of your engine regularly then of course a tight maintenence schedule is very important, however I rarely put my foot down and keep a good check on the oil levels and colouration and have never had any issue with any engine due to oil or filters.

I drive my Z daily and she's well maintained, she isn't over pampered or put to bed with a blanket and a hot water bottle.