[Closed] Engine Oil: Talk to me.

It matters

Isn't one the viscosity cold and the other number when warm?

It does matter. Too thin or too thick can wreck your engine I believe.

Yes it matters lots. Just accept it as a running cost and move on.

Hmm, see the geeks on a VW forum recommend 10w40 for my car, but Halfords etc recommend 5w30.

I'd like to believe the forum geeks because that would be cheaper. But who is right, and why? 15y old Polo.

Hmm, I'll consult the Haynes manual...

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Internet forumites are always right. :/

It's not just the weight, it's whether it's full or part synthetic or mineral oil also.

Some engines have bits that will heat the oil right up and will destroy mineral oil, hence part or full synthetic is required.

I would get the Haynes manual or better still info from the manufacturer (should be in the handbook I would've though) and ignore the internet. Halfords is probably a better source than the internet.

Edit - sometimes different viscosities are recommended for different climates also, worth finding this out as both could be acceptable in the UK.

You'll find there are cheap and expensive versions of each. They are just viscosity ratings which suit different cars. The lower number indicates the viscosity when cold and the higher number indicates the viscosity when hot. The 10w40 will have a bigger range in that respect than the 5w30. The 5w30 will be slightly thinner though, which can be better through the winter, but can also find leaks on older cars... The high end of the scale generally interests those who cane their cars, because that's when they'll be running hottest.

There's nothing much in it really. But quality of oil is something different altogether, and some will last longer than others. So long as it's changed regular, you'll be good. I'm no expert by any means though, so all of the above may be factually incorrect 🙂

My A4 seems to be ok up 200k on whatever's cheapest at GSF.

15 year old Polo? Run it on lard. Just change it at least every 6000miles.

Look your car up on opie oils, they usually have some deals on

I just got 6 litres of Shell 5w40 for £30

Diesel will use a different spec oil to petrol. The petrol engine oil will need to be resistant to thinning by unburnt fuel as well as contamination by combustion products. Find the cheapest one that meets the VW oil spec for your engine and change it more regularly than the handbook says along with the filter.

As above... 15 year old polo put what ever is cheapest you don't need full or semi syth... To be fare most people don't check nor top up so your already on a winner with what ever you find in Tesco bargin bin.
Changing every 6k or 12 months is far more important... (On a car of that age) without a turbo/super charger or modern high pressure diesel....

As somebody who has owned Alfa's I can assure you it is important. Do a little research. as above see what the manufacturer recommends. Then buy the best quality you can afford.

Go to your local vw dealer. The recommended oil I got from my golf from them was surprisingly cheap.

As someone who formulates oil for a living I can tell you that using oil with the correct viscosity and quality matters a lot.

Look up the recommended oil in the vehicle manual. You'll find it will recommend an oil with a certain ACEA and/or VW spec number. Then go and buy an oil that has that spec number on the container. As long as you have an oil that meets the required spec buy the cheapest especially for a 15 year old Polo.

real world: 15 year old basic polo... Specific oil my a##e... What would be worse incorrect viscosity or no oil or oil that's not be changed for 3 years...

Diesel and petrol version of my leon use the same oil. And it costs more than gold bullion 🙁

On an old Polo I wouldn't worry to much
It will have been designed around a mineral or at best part synthetic oil. If it was a new car I would start spouting about type's and brands, but it's not worth it for you.regular changes are best.

1995 Peugeot 205 diesel here. I ensure the correct spec and change every 3,000 miles because it only costs £20 with a filter. 18,000 miles / year and 60,000 under my ownership and it goes like a train.

Mine generally gets whatever is cheap (but appropriate) in halfords. Which at the moment, means mobil of some sort. But then I am not an informed buyer, I used to use castrol in the motorbike purely because it was a pretty colour.

I thought it was all sort of an amber colour (till you put it in, anyway)?

As you can see, no one can tell you. A huge number of differnt types of oil will work, some will give better protection from start up, some might be more resistant to high tempratures.
Given the age and milage of your engine it's not going to be overly fussy as it won't have tight tolerances, nor is it a performance car but you can buy something that is perhaps more suited to your requirements if it makes you feel better.

In this type of climate a 10W40 is fine, even a 5W40. On a cold winter morning for example, 5W40 will get up to operating temperatures quicker and will be circulating better than the 10W40 in the same time. It'll also be easier on fuel. This might be relevant if you just jump in the car and drive from cold.

As the viscosity changes with temperature you might want to runner a thicker oil if you were going to take your car to a track day, or if it was a high performance engine where you might see 120-130 degrees . But it's not so don't worry about it.

Cougar - Moderator

I thought it was all sort of an amber colour (till you put it in, anyway)?

The stuff I used was a nice pinky-red, reminded me of strawberry jelly.

Engine Oil: Talk to me.

You are HRH The Prince of Wales and I claim my £5.

As you can see, no one can tell you

Nonesense I just told him. RTFM and use an oil the manufacturer specifies.

uponthedowns

Nonesense I just told him. RTFM and use an oil the manufacturer specifies.

That's akin to answering someone who asks how to set up their full suss - "just read the f***ing manual and put in the manufacturers recommended settings". It's not wrong, but it's not helping the person understand what they are doing or why. In his car I'm sure it'll not make a good god damn what oil he puts in, and the manufacturers recommended oil will be fine but there are circumstances where someone may well want to deviate from the manufacturers advice.

This is not such a circumstance but he did ask what the different numbers meant and if it's your area of expertise you could share some knowledge instead of being condescending or snappy.

Any oil is better than no oil,if it's off the low mark on the dipstick,and you need to use the vehicle right away.( Most general grades of oil 5W 30, 20W 50,10W 40,should get the job done.),the W indicates oil will work in cold weather and the bigger 2nd number is the viscosity at around 210 o F,(100 o C),which it the same temperature as my Nan's front room!. Engine operating temp is given as 210 o F. I have got away with sticking even "Diesel" engine oil in to get to level. I never stray from reccomended grade. As jimjam has rightly said 10W 30 or 5W 30 fine in UK conditions. Oil cheaper than a siezed motor surely? 😉

Not applicable to your polo, but might be of interest to someone (if not oh well, I found it cathartic to post) modern diesels with dpf's need a low ash oil.

Regular oil changes are the vital part to getting a car to high mileage, and not stuffing it in the scenery helps as well.

Surely the manufacturer's spec number is most important? On the back there's a long list containing such things as VW504.00, VW507.00 etc

TBH, last oil change I had my brilliant local indy garage do it, cost me about £5 more than doing it myself and I threw in my usual bribe of biccies for the lads brewtime. They quote you for everything they do before work starts so I pay them cash. Sorted.

Ah, this is why I love STW. Post up 'the most boring question in the world ever' before bed, and come back after work to find a veritable anthology of discussion.

I'm just gonna pop out to Tesco for some cheap engine oil and then I'll settle in to read.

thegreatape - Member
Engine Oil: Talk to me.
You are HRH The Prince of Wales and I claim my £5.

*waves

*fiddles with ear

Given the age and milage of your engine it's not going to be overly fussy as it won't have tight tolerances, nor is it a performance car but you can buy something that is perhaps more suited to your requirements if it makes you feel better.

Did I mention that my Polo has a V8 in it?

My 1.8 Zetec powered Westfeild suffered sticking valves with 10w40 as opposed to 5w30 GTX magnatec.

Read all about oil on Bob is the Oil Guy [url= http://www.bobistheoilguy.com/forums/ubbthreads.php ](BITOG)[/url]

As long as your weight is correct and you change oil based on intervals/condition then dino (conventional) or sythetic probably doesn't really matter.

Synthetics usualy more resistant to high temperatures and pressure and therefore lasts longer (or at all) in a modern engine. Mineral or part synthetic breaks down with use, although some cars have it as running in oil for this reason as it allows the moving parts to effectively polish each other when theyre factory fresh and a bit tight. On an old engine anything will probably work, just change it frequently as cheap oil doesnt last and the engine will be filthy so your flushing out that crap.

10W40 means it behaves like 10 weight oil when cold and 40 when hot. That does not mean it gets thicker, but its only as runny as hot 40 weight oil, rather than hot 10 weight oil which would be really runny. So unlike a 'normal' oil its viscocity changes relatively little with temperature, which is a good thing.

Old cars might benefit from slightly thicker oil than when new. It helps the pressure remain high and stays put better. It also makes the engine a bit quieter.

I'd just use the right viscocity and type recommended by VW and get whatever is cheap. I usually pick up magnatec or mobil 3000 whenever asda has them on offer for <30quid a gallon.

My 1.8 Zetec powered Westfeild suffered sticking valves with 10w40 as opposed to 5w30 GTX magnatec.

Zetec engine ever built that runs on 10w40

thats a perfect example as to why its important to get the right spec oil then and not what the local motorfactors want to sell you 😉

Read The Engine Oil Bible: http://www.carbibles.com/engineoil_bible.html

Then go and ask your local independent accessory shop to get you a 10 litre or 25 litre drum of the right Comma oil or any other budget brand and change the oil and filter at the recommended intervals.

I used to do this with my old 1986 Landy with 225,000 miles on it and it ran like a sewing machine, happy as anything.

I bought oil for my vw from tps yesterday, worked out about £12+vat per gallon for the correct vw oil. About half the price it was in the local motor factors.

it ran like a sewing machine

If you'd used my wife's sewing machine you wouldn't use that simile.. 🙂

Hmm engine oil bible? Reads like an angry condescending forum poster. Also seems American i.e. of the low tech tin foil hat 'the corporations are out to get you' brigade. Is this for real?