bagwell

Currently for all 2014 Subaru vehicles, the car maker recommends changing the engine oil for every 7,500 miles (this is the minimum requirement).

But we have got confirmation from our Subaru source that, the manufacture will reduce the mileage number to 6,000, starting for all 2015 model year Subaru vehicles.

Different from most of other auto makers, Subaru uses horizontally opposed-cylinder engine (called “boxer engine”) in its cars. This type of engine has low center of gravity, which benefits the car’s handling. But this comes with expense that other V-shaped or I-shaped engine don’t have.

For example, because the cylinders are lying flat in the engine bay, the engine’s head gasket is immersed in the engine oil and also the coolant. Therefore the gasket will corrode more rapidly than other traditional engines, whose head gasket is not immersed in those liquids. For this reason, in some models Subaru installed sponges beneath the engine head gasket area to absorb the leaked oil. Another example is because of the gravity force, the lower part of the piston ring tends to receive more engine oil than the upper part, which causes uneven lubrication effect of the engine piston rings.

So for Subaru cars, it is good to change the engine oil more frequently. Unlike some auto makers that claim to have engine oil change interval well exceeding 10,000 miles, from my point of view the decision Subaru makes actually benefits its users.

Although someone may cite some UOA (used oil analysis) results to show it is still safe to change oil for xxxx miles, let’s not forget these facts: 1. from business aspect, what an auto maker really cares is to let your car run fine during the warranty period; 2. it is very hard to prove the engine piston ring/valvetrain wear is fully due to long oil change interval set by car manufacturer, this means it require great effort for you to claim warranty; 3. for some brands that cover all maintenance cost during warranty period, the less frequent the car requires engine oil change, the less cost for the car manufacturer.

I am not saying the oil change interval set by any car manufacturer is not correct. My point is: based on your user manual recommendations, you can treat your car better by exceeding the minimum requirements.

http://youwheel.com/2014/05/04/subar...ange-interval/

bagwell

my take is -- for a turbo car, I would stick to 5000 miles between oil changes.

Big Andy

There's no way I'd buy a car with that frequency of oil changes, it'd be forever in the dealership. My Lexus both required oil changes every 10k and it was a complete pain. My current BMW requires changes every 18k which is much more convenient.

mmarshall

The "Phase-One" Subaru N/A 2.5L flat-four had a history of head-gasket failures that wasn't necessarily associated with the engine being a flat-four at all. In fact, on the 1999-2003 versions, Subaru lengthened the engine warranty to 8/80 if a special factory-approved additive was poured into the engine's coolant. But that was only for the non-turbo 2.5s...not any of the other Subie flat-fours or sixes using the same cylinder-layout. Later versions of the N/A 2.5s have had more reliable head gaskets.

SLegacy99

The interval on my '05 LGT was 5,000. However, there were two (at least two) flaws that led to the recommendation of 3500 mile oil changes. 1. Turbo failure. The design of the filter that feeds oil to the turbo was poor. The filter itself was housed in a bolt and thus very tiny, resulting in filters that became clogged, starving the turbo for oil. 2. the pan only holds 4 quarts, when really it should have been more like 6. I have found on every Subaru that I have owned that they always need to be topped off part way through the interval due to consumption. ...yet I have never had a Subaru that was visibly burning oil.

I would say that 6,000 miles is pretty decent. Far better than years ago when we changed our oil every 3000 miles. I will likely stick to 5000 mile intervals when my WRX arrives...if it ever arrives.

bagwell

uhhh that's fine for bmw lease car.....not for anything else that I'd wanna keep.

mmarshall

Your BMW, unless it is a fairly old one, probably has a oil-monitoring computer which calculates oil-change intervals based on a number of different driving-factors....average engine temperature, number of cold-starts/warm-ups, number of heat-soaks, amount of stop/go driving vs. steady-state cruising, date of the last oil change, etc....

BMW, though, had trouble with some of those early oil-monitoring-computers, and ended up replacing some expensive engines under warranty because the computers screwed up and allowed the oil and its additives to deteriorate too much and damage things. The newer ones, of course, have been much better.

chikoo

Only because BMW pays for it, and by the time the engine fails, it would be out of warranty anyways.

4TehNguyen

iTrader: (1)

our TSX and Honda Pilot wont go past 10k miles on a synthetic change. Proven with an oil analysis done on both cars. Throw a turbo in the equation and the oils shot long before 15k miles like what BMW "recommends"

Subaru isnt the only one to reduce OCI
http://www.e90post.com/forums/showthread.php?t=868291

bagwell

for the 2015 WRX + STI....from the owner's manual

geko29

I went 17-19k between changes for 12 years and well over 100k miles on an E46. When I took the valve cover off at around 84k to replace the VANOS seals, the valvetrain was PRISTINE, with just a thin coating of golden-amber oil (that had been in the engine for 18k miles). I actually had a UOA done once after 18k miles, and the lab said the oil was still well above minimum standards and safe to continue using. Of course, I had already changed it, but it provided nice peace of mind.

The extended interval on BMWs is absolutely realistic for the long term, as long as you use a quality oil and filter. They have a very large sump (7 quarts on my little 2.5L I-6), which means the oil works half as hard as it does in many other cars. Factory fill is German Castrol, which is an excellent full synthetic. I used Amsoil European Formula for the vast majority of the car's life, which I intend to continue with my E90 once the free maintenance expires. I fully expect to get 150k miles or more without any oil-related issues.

Big Andy

+1.

Mine's at 80k miles, had 4 visits to the dealership for oil changes. Runs like new and has had zero problems. The long-life oil they use is excellent.

My 2 Lexus were excellent (and if you forced me to choose I'd take my IS's over my 3 series) but they were expensive to run with the 10k service intervals, had too many unscheduled visits to the dealer for warranty work, and suffered from inferior quality paint and wheels (a new set of wheels every year under warranty for each).

IS350jet

This is such blatantly false information it's pathetic! I feel sorry for anybody that actually believes this.

bagwell

right. that's why they changed the OCI....

mmarshall

Keep in mind, though, that, in most cases, oil is SUPPOSED to turn dark with age. if it doesn't, it might not be doing its job, which is to keep micro-small particles in suspension that are too small for the filter-element to trap and hold. Those particles are what makes the oil turn from amber to brown to black over time.