is Regular oil safe for '03 BMW?

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Novice question from a novice oil guy with no mechanical prowess or knowledge--but need advice badly from ppl who know cars and oil!! I recently inherited a 03 bmw 325i, about 90k miles, car manual recommends 5w30 or 5w40 fully synthetic oil (so far only synthetic oil has been used). What would happen if I added REGULAR 5w30 oil in my car? Will regular oil damage or harm my engine over time. If so, please explain and specify how. I drive in normal conditions, in a fairly sub-urban area, upstate NY, do not race but do occasional spirited driving. I have asked several mechanics but all have told me its not a good idea except none of them can explain why or give a clear reason. When I went to the BMW dealer, asking that question to a technician gets them little angry and I got a hurried response, they told me to "do what I like outside at any garage". That was really embarrassing. To my understanding oil’s main function is to act as a lubricant so why not the use of regular oil in my engine? Or does BMW want consumers buy more expensive materials,be exclusive, that is not completely necessary? As I have read online, in Europe, many car owners do not even use synthetic oil as Americans do but there cars run very long. Not interested in blending. I also know that synthetic oil is superior to regular oil. I just started working and am paying off student loans and cant afford the $100+ to do an syn.oil change and I dont want to unless I know its completely necessary i.e. damage to the engine, etc. Advice needed, Tobin, 23, New York
 
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One of the main reasons BMW wants you to use synthetic oil is that they expect you to run longer intervals... 10-15k miles (if you follow the on-board oil change light). A typical mineral oil will not hold up that long. And if you have to change it 2-3 times as often, then is it really cheaper in the long run? If you're on a budget, then do your own oil changes - 7 quarts of appropriate synthetic oil plus an oil filter will cost you about $50. Also, one of the requirements for BMW oil is relatively high HT/HS. You will not find a 5w-30 mineral oil that meets it. High HT/HS ensures an oil film is not broken when you're doing your "occasional spirited driving".
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As I have read online, in Europe, many car owners do not even use synthetic oil as Americans do but there cars run very long.
I guess it depends who you talk to. All newer cars in Europe run pretty long OCIs - 20k km or every 2 years. Most mineral oils don't hold up well over such long intervals. I'd be surprised if those owners really run mineral oil in their cars. My parents who live in Europe have cars that are not that young anymore - a '99 Nissan Primera and an '02 Volvo S40. Both those cars call for synthetic oil, and when they go for service, that is exactly what they get.
 
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JHZR2

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If you do it yourself, it will not be $100, and you'll be able to recoup the cost by longer drain intervals, if you use a bmw long-life spec oil. There are a variety of reasons why dino oils are not sufficient, including the requirement for robust hths viscosity - all bmw spec oils are aces a3, and no decent dino oils in the correct viscosity are. 10w-40 dino would be the closest to reasonable protection available in a dino oil, but given the VII requirements, the oil will shear down quick and need to be changed more often. You might consider running chevron delo in 15w40, or if you can find it, 10w-30 versions of shell rotella or chevron deli, as either will be more robust. None are optimal, and you'll need to change oil far more often than if going with syn. I'd pick the right oil - I'd use m1 0w-40, use the oil life monitor to it's fullest extent, and do what is right for the car.
 

Tobin

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What is HT/HS stand for? and when this film is broken what happens next? I will definetly have to look into learning to do an oil change if i understand why synthetic oil is required lol In Europe and Asia I read some BMW owners use regular oil but they do not wait 10 to 15k intervals to do an oil change.
 
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HT/HS - high temp / high shear stability. When the oil film is broken, two pieces of metal come in direct contact with each other - this causes excessive engine wear.
 
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My sister in law tried running dino in her BMW...and with her driving, it really was a big no-no. I'm guessing you could (she did for nearly 1500 miles-didn't hurt the car), but with the crazy weather in the northeast, and city driving, I would put synthetic in it, even if it had to be wal mart oil...
 

Tobin

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Ohh I see, so your saying my BMW engine gets unusually hot during spirited driving..causing the film to wear out during this type driving? So does that mean the BMW engine gets hotter than a Nissan sentra if you compared both engines during spirited driving?
 

Tobin

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To JHZR2 You said 10w-40 dino would be the closest to reasonable protection available for REGULAR oil...but your saying it requires more changes because it cannot hold up in shearing. So is changing the oil every 5k miles a good rule of thumb for this grade of oil in my car?
 

Tobin

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QOUTE from QAUTTRO PETE--->Also, one of the requirements for BMW oil is relatively high HT/HS. You will not find a 5w-30 mineral oil that meets it. High HT/HS ensures an oil film is not broken when you're doing your "occasional spirited driving". Ohh I see, so your saying my BMW engine gets unusually hot during spirited driving..causing the film to wear out during this type driving? So does that mean the BMW engine gets hotter than a Nissan sentra if you compared both engines during spirited driving?
 
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 Originally Posted By: Tobin
Ohh I see, so your saying my BMW engine gets unusually hot during spirited driving..causing the film to wear out during this type driving? So does that mean the BMW engine gets hotter than a Nissan sentra if you compared both engines during spirited driving?
Maybe not necessarily hotter than a Nissan Sentra engine, but BMW engines have typically high output and the construction is such that it puts the oil through some serious paces, so you want an oil that is very stable and still doing its job under those conditions. Then again, I am not a BMW engineer, so I cannot tell you how they determined that an HT/HS of 3.5 is good, but 3.4 is already insufficient. Forget the HT/HS. Focus on the drain interval - you can go twice as long on synthetic than on mineral, so you're saving time and labor costs. Wouldn't that in itself make a good argument for using synthetic oil? Are you also not running premium gas in it?
 
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 Originally Posted By: Jaymus
BTW, how can I find the HTHS of oils?
Some companies show it in their literature (PDS) on their websites. Some don't. I have yet to find out HT/HS for the new Castrol Edge stuff.
 
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I kinda think that changing oil every 5k using dino vs every 15k using syn is going to end up costing you more. Stick with the syn, especially if you are going to do spirited driving.
 

JHZR2

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Regarding the 10w-40, yes, you'll need to change it more often, wasting time and resources, and not saving nearly as much money as you'd think. There is nothing special per se about the bmw engine, but it does put out a fair amount of power in a small size, and tolerances and clearances are set up a certain way. Their output profile and performance is set up a specific way, and the manufacturer isn't dumb in what they spec. A 10w40 will shear and create deposits earlier/quicker. In the summer the 15w-40 would be ok (I'd suggest chevron delo), but I'd say it isnot suitable for winter use. The 10w30 variant would be a better choice but I doubt you'll find it. I'd say to not be penny wise and pound foolish. Use the right oil, get the AT serviced, and drive the car another 100k
 
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If you plan to follow the on board oil life monitor, and change the oil when the maintenance indicator comes on, you need to use an oil specific to BMW's factory specs. I believe that is BMW LongLife-01. Check your owners manual to be sure. I think your engine takes 7 quarts, plus a filter. There aren't many oils that meet BMW LL-01 that are readily available. The two most common are Mobil One 0W-40 and Castrol Syntec 0W-30. Either would be an excellent choice for your car. Cost is around $6.00 per quart and I believe your engine takes 7 quarts. BMW's house brand 5W-30 meets the spec, too, I believe. It's available online or at your dealer. Also, you'll need a cartridge-style oil filter which will run you $10-15, a little cheaper if you buy it online. So, the total cost for parts alone is around $55-60. Now you can see why the dealer charges $100 for an oil change when you factor in labor rates. One idea is to buy the parts yourself, stock up when you find a sale, and take your car to an oil change place and see if they will do the oil change using your parts at a discounted rate. You might be able to have it done for $75, parts and labor. Not a big savings but it's something, right? Beyond taking it to the dealer or an oil change place that uses the correct oil, your only choice is to DIY. Can you use conventional oil instead of synthetic and save some money? Yes, but its not really a savings. You'll have to do oil changes twice as often and using a quality conventional plus oil filter will cost you $30-35 in parts, plus labor. Most oil change places will charge you extra past 5 quarts of oil, so I don't think you'll find much savings there. So, spend $35 every 4-5000 miles, or $75 every 10-12000 miles. You do the math. European cars are not cheap to maintain and yours is proof. But, if you calculate it out a bit, it's really not that expensive.
 
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Nobody mentions an oil like RTS 5w-40. While it won't meet all the Euro spec's ..it should be able to handle what the engine throws at it and have decent longevity in service.
 
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 Originally Posted By: Tobin
Not interested in blending. I also know that synthetic oil is superior to regular oil. I just started working and am paying off student loans and cant afford the $100+ to do an syn.oil change and I dont want to unless I know its completely necessary i.e. damage to the engine, etc. Advice needed, Tobin, 23, New York
If you can't change your own oil, just buy the oil at Walmart and take it to an oil change place. Most will let you bring your own oil (some will give you a slight discount) and you should be be able to get a 5-quart jug of Mobil 1 5W-30 or 0W-40 for about $22 these days. That should bring your total cost to about $60 or less. You can safely use M1 5W-30 Extended Protection for 12,000 miles (they guarantee it for 15K miles) which would be $26 at Walmart for a 5-quart jug (not sure how many quarts you need). And no, they don't specify synthetic oils because they are snobs.
 

JHZR2

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 Originally Posted By: Gary Allan
Nobody mentions an oil like RTS 5w-40. While it won't meet all the Euro spec's ..it should be able to handle what the engine throws at it and have decent longevity in service.
true, but it isnt THAT much less $$$
 
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