Hi Everyone, I'm new around here, but I've loved reading the forums so far and I've gotten a lot of useful info. My question may be redundant (sorry if this is a 10x repeat question), but I am in the process of buying a 1990 535i/5spd w/ 184k miles, and I need to know what kind of oil to put in it. I'm a huge fan of mobil1 0w-40 oil, but i'm worried that an extremely thin oil will seep out of the old motor because of the old seals and gaskets. I'm wondering if anyone else has experience with a high milage synthetic (from mobil1 or elsewhere) that's thicker, say a 10w-40?

Valvoline 20w50 during warm months
...Mobil 1 HM 10x40 in winter months.

I feel the thicker oils quiet the engine better and coat the parts longer between runs.

Search around here...there are many other threads that speak to this ;)

Hi Everyone, I'm new around here, but I've loved reading the forums so far and I've gotten a lot of useful info. My question may be redundant (sorry if this is a 10x repeat question), but I am in the process of buying a 1990 535i/5spd w/ 184k miles, and I need to know what kind of oil to put in it. I'm a huge fan of mobil1 0w-40 oil, but i'm worried that an extremely thin oil will seep out of the old motor because of the old seals and gaskets. I'm wondering if anyone else has experience with a high milage synthetic (from mobil1 or elsewhere) that's thicker, say a 10w-40?

Mobil 1 0w-40 is a 40 weight oil, so I would hardly classify it as thin.

In general high mileage oils are formulated on the heavy weight of the weight scale for their given weight and have seal swellers to help minimize oil leaks. They are worth using.

In your case, the Mobil 1 10w-40 is an excellent choice. It provides a good weight range for year around use, except the coldest climates (less than -10f or so). It also offers a nice high HTHS of 4.06, and has more than adequate ZDDP levels for anyone concerned that cam wear may be exasperated under the new lower levels some oils are using. Finally, it available in the 5 quart jug for about $22 from Walmart.

Mobil 1 0w-40 is a 40 weight oil, so I would hardly classify it as thin.

In general high mileage oils are formulated on the heavy weight of the weight scale for their given weight and have seal swellers to help minimize oil leaks. They are worth using.

In your case, the Mobil 1 10w-40 is an excellent choice. It provides a good weight range for year around use, except the coldest climates (less than -10f or so). It also offers a nice high HTHS of 4.06, and has more than adequate ZDDP levels for anyone concerned that cam wear may be exasperated under the new lower levels some oils are using. Finally, it available in the 5 quart jug for about $22 from Walmart.

thanks a lot! this is my first bmw and i don't want to mess it up! i live in oregon in the summers and go to college in seattle, so i'll never see a temp less than 25f, so 10w-40 it is!

thanks a lot! this is my first bmw and i don't want to mess it up! i live in oregon in the summers and go to college in seattle, so i'll never see a temp less than 25f, so 10w-40 it is!

It will be a good choice for you, change it every 7500miles or according to your service indicators and don't worry about it.

BTW, laughing at the photo in your sig line. I have been there and actually toured the museum next to the 4cyl building.

It will be a good choice for you, change it every 7500miles or according to your service indicators and don't worry about it.

BTW, laughing at the photo in your sig line. I have been there and actually toured the museum next to the 4cyl building.

haha thanks. i was creative enough to go on google images for that one, the car doesn't look good enough to pull out the trusty 35mm yet, but once it does i'll photoshop a little something.

By the way, is 7500 really a good interval for oil change? That seems long to me, but of course I'm used to every 3000 on conventional, synthetic must be that much better.:)

The 3000 mile interval is about 30 years out of date. The OCI meter on your car was set up with Mineral oil in mind, and is more than adequate running synthetics.

If you look through the used oil analysis on bobistheoilguy you will see that even with mineral oils, unless there is something wrong with your engine, intervals of less than 5000 miles are a waste of money.

haha thanks. i was creative enough to go on google images for that one, the car doesn't look good enough to pull out the trusty 35mm yet, but once it does i'll photoshop a little something.

By the way, is 7500 really a good interval for oil change? That seems long to me, but of course I'm used to every 3000 on conventional, synthetic must be that much better.:)
Even on synthetic, I wouldn't keep it in for over 5000 miles. I don't believe in the long intervals ... and if you do, just go find any newer BMW and open the oil cap ... sludge and burnt oil out the ass.

3000 mile intervals and conventional oil and a perfectly clean, no leaks engine here. :buttrock

you can keep it in for longer intervals but it all depends on the service of the engine. unless you know what you're doing you can cause damage. if your not doing a lot of city driving or a lot of cold starts you can extend it. there some ways to test the oil and find out possbily by a lab.

If your switching from old school oil to synthetic you probably want to shorten the change interval for the first change.. you never get ALL the oil out of the engine when you change it.

If your switching from old school oil to synthetic you probably want to shorten the change interval for the first change.. you never get ALL the oil out of the engine when you change it.

good thought. i actually looked in the car, and the previous owner had taken it to jiffy lube about 1k ago. no idea what kind of oil is in it, but taking that stuff out is my top priority right now.

jiffy lube.. haha.. yuck

my 1990 535i/5 with 183k miles


I've been using Mobil 1 10w30 Extended Performance (high milage) and its been great. I live in SC so the weight seems perfect.

I try to change it between 3k and 5k, never more then 5k miles

I enjoy German Castrol (search) 0W-30.

If your switching from old school oil to synthetic you probably want to shorten the change interval for the first change.. you never get ALL the oil out of the engine when you change it.

*attaches garden hose to oil cap and reaches for knob* :shifty

btw, don't the v8s use even more oil than the 6s?

5 quarts won't be nearly enough oil.

lubro moly 5w-40

Even on synthetic, I wouldn't keep it in for over 5000 miles. I don't believe in the long intervals ... and if you do, just go find any newer BMW and open the oil cap ... sludge and burnt oil out the ass.

3000 mile intervals and conventional oil and a perfectly clean, no leaks engine here. :buttrock

+10000000!

It isn't always just how the oil is holding up, but also the oil filter, and how much gunk accumalates in the engine (which is highly due to the gas itself and the environment). Here in SoCal San Diego we are blessed with pretty good weather and rather cleaner air in the area I am in, but go to a place like LA, and you will find your oil get dirty MUCH faster. It also has a big part in just how you drive. Manufactorers may recommend 10-15k mile oil changes, but their conditions are light driving. Light driving for them consists of 90% freeway in a perfectly clean environment and driving at least 10-20+ miles allowing the engine to get up to full operating temperature. The truth is virtually no one falls under that requirement, which leaves you to the heavy driving place, which is more like 3-5k miles.

As for synthetic oil vs mineral oil, I will use mineral oil every time on my old engine. Thicker oil lubricates better, and while you may not have those extra 3-5 ponies from the synthetic, I would rather drive knowing that the engine is well protected, especially in its older age. Also remember that the oil filter is going to accumalate the filth from the combustion process regardless of what oil you use, and will do so at a steady rate, which means oil will also accumulate all this filth, which makes up for the majority of sludge. I would rather change my oil myself ever ~3k miles for $25 knowing my engine is going to stay very clean than change it every 5, 7.5 or even 10k miles for $40-50 and worry about sludge buildup.

Personally, I stretch my changes on synthetic (RP 10w40 for now then switching to 15w-50 Redline) to about 7500-10k and change my filter every 3k. Never had a problem this way.

I do 3-4k miles for changes. But I'm running 20w-50 dino oil year round in south Louisiana. Change the filter every time (duh)