What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - RobH_2024

Bought a old Peugot 207 a few months ago. It's showing the low oil light when I start it. Had a check using the dipstick and the level looks OK, but the dipstick isn't 'holding' very much oil when I pull it out, so might not be accurate. Simple solution is to ust top up the oil to be safe.

Problem is I don't know what oil the previous owner used. No indications of the correct oil to use in the car manual or on the service record!!! A check online suggests all 207's from that era use OW-30, and some can use 5W-30 as well.

Safest bet is therefore to use 0W-30. But what if the existing oil is 5W-30, will mixing the two oils cause any damage? Want to try and avoid having to do a full oil change in a garage (also not too keen on driving it to the garage if the oil is very low).

Any advice welcome!!

Ta

Rob

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - paul 1963

Can't see any harm in mixing although I'd be tempted to do a oil and filter change, cheap easy job and at least you'll know what's actually in it.

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - elekie&a/c doctor
5/30 is perfectly fine for this age of vehicle. You may find the dipstick doesn’t read correctly because the plastic graduation marker at the bottom of the stick has broken off . So you’ll get a false reading.
Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - Andrew-T

Presuming your car is petrol, not diesel, or the dipstick would show black oil ? If the car has a handbook, that will offer two or three alternative grades of oil. Unless it is an unusual type for certain engines, it should be safe to mix grades of semi-synthetic within the range listed in the handbook.

Your low-level indication could be because the oil actually is low, or the level sensor is misreporting. The dipstick is a more reliable indicator, so if you have any doubts about that, get a replacement - they aren't expensive (E-bay). Are there any oil drips under the car ?

Edited by Andrew-T on 29/04/2024 at 15:34

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - RobH_2024

Hi

Thanks for your replies, I'll stick some 0w30 in. Car is petrol. Havent seen any evidence of leaks but I'll have another check [as well as using the dipstick again] before I put any more oil in. There were oil marks on the dipstick above the 'min' level, but none of the marks were very clear. Will try leaving the dipstick in for longer to see if that helps.

I'm a couple of months away from the MOT/ full service so just want to keep it going until then if possible, before letting someone have a proper look at it.

Thanks

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - elekie&a/c doctor
What is age of car and engine size ?
Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - Andrew-T

There were oil marks on the dipstick above the 'min' level, but none of the marks were very clear. Will try leaving the dipstick in for longer to see if that helps.

It's always best to read the dipstick in a cold/cool engine, on a level surface - straight after switching off will never give a true reading, and the oil is less visible too !

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - Rerepo

ok to mix. But buy a new dipstick.

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - gordonbennet

There were oil marks on the dipstick above the 'min' level, but none of the marks were very clear. Will try leaving the dipstick in for longer to see if that helps.

It's always best to read the dipstick in a cold/cool engine, on a level surface - straight after switching off will never give a true reading, and the oil is less visible too !

Worth checking in the handbook, on our Subaru and Landcruiser the preferred method is warm engine wait a few minutes after shutdown and then check the level.

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - Andrew-T

<< Worth checking in the handbook, on our Subaru and Landcruiser the preferred method is warm engine wait a few minutes after shutdown and then check the level. >>

I quote from the handbook from my 207, 2007 edition :

"The reading will only be correct if the vehicle is on level ground and the engine has been off for more than 15 minutes."

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - edlithgow

You seem to be having difficulty reading the dipstick.

A wipe-off with a suitable clean tissue, such as a hard-ish grade of toilet paper or hand-towel that wont shed lint, should remove any splash from engine operation.

If there are congealed rings of oil or dirt that are making it difficult to read, cleaning with a suitable solvent (petrol, kerosene, , acetone, white spirit, meths,vodka many etcs) should help.Just wet a tissue, wipe dipstick and then wipe dry with another one. This should not be required routinely

Having cleaned off your dipstick, carefully re-insert it, avoiding contact on the way in as much as possible,(perhaps guide tip with your other hand close to the target, retaining the tissue for the purpose) wait for a few seconds, remove and read

Lighting will influence ease of reading, so adjust appropriately, perhaps keeping some kind of lamp or torch in the car for the purpose.

I've never used anything as watery as 0W-30 and wouldn't want to, but I imagine it might be a bit harder to read than a higher base viscosity grade of oil.

There are reports of negative outcomes (gelling) from mixing oils. These wrecked engines, but they happened in extreme low temperatures in the US, and this phenomena is unlikely to affect you, though in general its probably better to avoid mixing oils.

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - RT

It's the hot viscosity that's important to get right in any engine, the -30 in the OP's case.

For 3 decades now, I've used the lowest cold viscosity with the rated hot viscosity - that gets oil around the engine fastest when it's cold and warming up - which is when most engine wear occurs - I'm presently using 0W-30 in my 3.0 TDi VW which is rated for 5W-30 - but importantly I do ensure it meets the correct VW specification.

If only 5W-30 was available for my top-ups I'd have no issue adding it to the 0W-30 in the engine.

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - edlithgow
I've used the lowest cold viscosity with the rated hot viscosity - that gets oil around the engine fastest when it's cold and warming up - which is when most engine wear occurs

Thats the story, sure.

Might even be true, sometimes, but the (rather few) actual studies I've seen of the effect of oil viscosity on engine wear, tend to show it goes up,a little, as the viscosity goes down.

Achieving these hot viscosities with a low base viscosity requires a lot of viscosity index improver and these can tend to clog oil control rings with their degradation products.

This doesn't matter much to me, since something other than engine wear (usually THE MAN in some form, oft abetted by my mechanical incompetence) has tended to kill my cars, but its not a big surprise if the studies differ from the advertising copy..

Edited by edlithgow on 02/05/2024 at 05:39

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - edlithgow

For 3 decades now, I've used the lowest cold viscosity with the rated hot viscosity - that gets oil around the engine fastest when it's cold and warming up - which is when most engine wear occurs - I'm presently using 0W-30 in my 3.0 TDi VW which is rated for 5W-30 - but importantly I do ensure it meets the correct VW specification.

My late lamented Skywing had very little carbon on the piston crowns and in the ring and oil control grooves, despite being ancient, and running a bit rich by the plug appearance.

This could be due to sometimes using liquid water decoking in the running engine ( though I believe this may have caused spalling damage to the cylinder walls, and wouldnt do it again. I would use steam instead, which might have other Smokey Yunik stylee advantages)

It could also be due to the use of relatively high viscosity oil with a relatively high detergent/dispersant content, a relatively low viscosity index improver content, and a relatively low volatility.(I used a 1 to 1 mix of CPC SAE 40 and Mobil Delvac MX 15W40)

Low viscosity oils tend to be more volatile, as per the NOAK volatility test, and such volatiles are more likely to be carried over entrained in blowby gases via the crankcase ventilation system and burnt.

Low viscosity oils are probably also more likely to pass the piston rings and be burnt directly. Both tendencies will be aggravated by higher compression ratios and turbo-boosting.

Discussed here, with a technical contribution by Sonofjoe, whos also been on here.

bobistheoilguy.com/forums/threads/how-common-are-s...2

He also suggests (I think plausibly but speculatively) that more stable synthetic oils might actually produce more combustion carbon deposits.

The Skywing didn't use much oil.

The Skywing's engine also got a lot cleaner generally (outside the combustion chamber) during the 10 years or so of my ownership. (as seen under the valve cover and in the sump) loosing the extensive varnish sheets it had when I bought it.

This cant be due to steam cleaning or lower volatility (which would only affect the combustion chamber) and probably wasn't down to lower viscosity index improver content either. My guess would be that the relatively high solvency of the Group 1 SAE 40, combined with the dispersancy/detergency of the Delvac, shifted the varnish, while my mileage was too low for extensive oxidation of the inherently less stable non-synthetic oil.

All a bit speculative, based on anecdotal evidence, as is yours.

But I prefer my anecdote. No creative input from VW, for one thing.

Edited by edlithgow on 17/05/2024 at 07:23

Peugot 207 - Is it OK to mix OW-30 and 5W-30 oils? - Gibbo_Wirral

There's a good chance it will need 1 litre of oil every 1000 miles or so.