What oil do you use in your car?

[G35COUPE]

I always see Royal Purple ads flashing around the forum. I am a Royal Purple fan. Thats all I use on my G-35 Infiniti Coupe (5W-30 synthetic oil). Excellent oil. It has served me well, with the way I drive. Quick start up time, and great when you want to flog the car. It also allows the car to rev up slighlty faster. I change my oil every 2,000 miles because of how I drive. I have been using synthetic oil since 3,000 miles in my engine.

I use Castrol GTX 20W-50 in the B13 Nissan. Excellent oil for that engine. Maybe thats why the engine has lasted 260.000 miles with daily flogging. Oil change = 2,000 miles.

I know this might seem excessive for some, but i can tell the difference in engine performance when I drive with fresh oil versus an aging oil. I need my engine to be ready for flogging all the time.

[pimento]

I used to change the oil in my mini when it started running rough (every 3-5 months) with whatever was on special down at AutoOne. That might be why by the time I sold it first gear didn't work and the crank bearings were stuffed.

[hec16]

beer don't have a car in argentina just mine in guatemala jaja

[70cuda88]

I currently use Castrol Synthetic in my E36 BMW. Running extremely smooth after 175000 miles and an accidental transmission fluid change.

[DesmoRob]

The mercedes service reports are telling me syn 5w30 synthetic. My guess is that first 'syn' stands for Castrol Syntec.

[Cobrafan427]

I use Shell 10w-30 in my 1990 Crown Vic and i've nvr had a problem w/ the internals, now all the other little stuff is a diff. story but the engine runs pretty good. Only actual problem i have is that it leaks the oil that i put in and i have to refill it about every month or two

[Dino Scuderia]

Synthetic is not needed in 99.9% street car applications.

Synthetic oil is designed for extreme conditions like extreme heat or extreme cold...that's where the synthetic molecules stretch without breaking apart unlike in conventional oil.

Synthetic oil also helps in extended oil change intervals like 7500 miles and over.

Paying extra for the synthetic is a waste unless you have a turbo or need to crank your car in extreme cold.

I used to sell industrial and automotive lubes...this is from the teaching of the lube engineers.

7500 miles used to be standard oil change interval for conventional oil...but when smaller motors became the norm and various ancillaries which increased engine heat came along recommended intervals began to drop.

[Matra et Alpine]

DIfferent national standards for oil specifications are now VERY confusing.

Synthetic isn't necessarily synthetic

The RX-8 owners hit this all the time as Mazda say ONLY to use non-synthetic and ONLY recommend their own -- at a higher cost per litre than a good malt whisky

Thankfully we've some oil experts and most in the UK use Fuchs oil which is LISTED as a synthetic, but it isn't fully !!

re oil longevity, the power/litre increases over the year are the main reason for the shortened life of normal oil and the need for performance oils.

How an oil acts at start up is critical and where modern synthetics usually win over "ordinary" oils. It's the most critical time for the engine.

THe main reason an RX-8 can't use a FULLY Synthetic ( Like Mobil1 ) is that it doesn't burn fully and clogs up the plugs and gums the rotors. Nobody else has that issue

[Dino Scuderia]

How an oil acts at start up is critical and where modern synthetics usually win over "ordinary" oils. It's the most critical time for the engine.

Yes it's pretty much always been said that most wear occurs at start up...but in all my years in the business I never read a tech bulletin that concluded an engine failure was due to excessive wear on start up.

Any engine which has had oil circulated through it then shut off doesn't have metal internal parts that magically become bone dry or in a state prior to having contact with a lubricant. There will always be a thin film of oil on that metal which is all that's separating the parts when the engine is running anyway.

Most people buy synthetic oil because it's recommended in their owners manual, or they simply feel better because they think they are doing the best for their engine, or they no nothing about oil but their favorite race team uses it, or like the original poster in this thread who thinks because he flogs his car he needs it and it's an expensive car.

[baddabang]

Mobil 1 full synthetic.

/thread.

[drakkie]

Shell Helix semi-synthetic 5W30 on ACEA A3/B3 spec with Ford MC 912.33 specification.

Why not mineral oil ? Well since it's damn hard to get in my area in the required specification. Costs about 13 Euro per litre. My car uses about 1l/1100 km these days and every two months or 8.000km i refresh it.

The old Suzuki allways gets 15W40 cheap as shit Shell Helix oil. It does not use a single drop.

[G35COUPE]

Yes it's pretty much always been said that most wear occurs at start up...but in all my years in the business I never read a tech bulletin that concluded an engine failure was due to excessive wear on start up.

Any engine which has had oil circulated through it then shut off doesn't have metal internal parts that magically become bone dry or in a state prior to having contact with a lubricant. There will always be a thin film of oil on that metal which is all that's separating the parts when the engine is running anyway.

Most people buy synthetic oil because it's recommended in their owners manual, or they simply feel better because they think they are doing the best for their engine, or they no nothing about oil but their favorite race team uses it, or like the original poster in this thread who thinks because he flogs his car he needs it and it's an expensive car.

Speak for yourself. I disagree with you 100%.

1. Driving habits and conditions should dictate the frequency of oil change. Your 7,500 miles assumption is simply that---an assumption. Engineers of these cars assume that on public roads, with the characteristics of the oil they put in the car, that you will drive these cars normally. For this, my manual tells me to change the oil every 3750 miles. So, what happens if you don't drive the car normally??? What happens if you suddenly change brands of oils?? Do you continue to use the same oil change frequency as noted in the manual, given that the additional heat generated in the car will likely break down the engine oil much differently in relation to the brand of oil used, than the recommended 3750 miles will allow, and given that the basic function of the engine oil which is to lubricate the engine, becomes questionable with time and use?

2. From my driving experience synthetic oil seems to allow the engine to rev less stressfully than conventional or blend oil. I know because my car came with a blend engine oil, and when I changed it to synthetic, the difference in revs was like night day. Now, if the argument was between conventional and blend versions of oils, then i might start agreeing with you that the difference between blend and conventional oil, is meaningless. I KNOW because I have used conventional, blend, and synthetic.

3. The most basic and primary function of oil is for lubrication. The harder it is for the oil to break down, the better the oil. Synthetic oil is more resistant to breakdown than conventional oil. So, can you describe what is wrong with using an oil that does nto break down as easily??? The number one enemy of any engine is heat. And if the oil can help reduce heat generation or protect the engine for much longer periods during more intense use, then, it should generally be good for any engine. Whether or not a person considers it waste to use such oil, at this time, is a matter of perception, to say the least.

4. And you cannot dispute this. The newer the engine oil, the better it is for your car. Period. No engineer will dispute this. If you feel it is a waste of money to give a car new blood, I am sorry, it is not a waste for me and many others, especially if you love the car enough, or drive it to where the designers of the car would consider the way you drive to be abnormal use. Now, tell me, when you go into your kitchen to fry some battered fish, do you prefer used oil or do you prefer fresh oil?? How does the fish look with used oil versus fresh oil?? How about the taste of the fish when you compare used oil versus fresh oil?? Again, this is a classic everyday description of the essence of fresh oil, where ever it is required. The same goes for an engine, however, the case of an engine is more complicated than the fish fry example.

5. Now, combine heat resistance of the oil with freshness of the oil, and you get a formulae that automatically protects an engine well beyond the design limits. I KNOW. My B13 has 260,000 original hard miles on it because I replace its oil far frequently, with a conventional oil, which happens to be one of the best conventional oil out there (Castrol GTX 20W-50). My B13 still uses its original timing chain and it has never been replaced, ever, ever, and i still flog the heck out of it. Timing chain uses your engine oil to stay lubricated. Why is this timing chain longevity possible??? Greater frequency of oil change with excellent brand of oil. I know people who have replaced their timing chain twice over, already.

6. At the end of the day, you cannot convince a person that oil will still be useable and practical at such an extended use. Remember, the engineers of these cars could not possibly replicate every environmental factor in the design of these cars. I KNOW this because I and my technician have actually discovered a procedure to perform a specific task in my car, eventhough Infiniti has nowhere in their manuals and directives, on how to perform that function the way we i and my technician have done. We literally taught Infiniti how to work on their own car. It was an experiment that turned out perfectly. In the same vein, the engineers of these cars sometimes don't know how the car will behave under some conditions. They only know how the car will behave under the conditions they have set for the car. Unfortunately, reality does change things a great deal.

7. Now, I will be the first to tell you that if you drive your car normally on a daily basis, then Royal Purple is way too excessive for daily driving. I KNOW because i once used Mobil 1 synthetic, and i saw no difference between mobil 1 and Royal Purple under normal driving conditions, in terms of how my car behaved.

The difference between Mobil 1 and Royal Purple exists somewhere at about 5,000 RPM+ and beyond, which is where i generally operate, and suddenly, its like night and day. Mobil 1 cannot touch Royal Purple. Mobil 1 is not a real synthetic oil. It isn't even close. The only engine oil that Mobil makes, that i know, that is at par with Royal Purple is their Mobil OW-40 Synthetic oil, which the GTR uses. The 370z and G-37 come with a different type of expensive and propietary oil that is manufactured by Nissan for the VQ37HR and VQ35HR engines.

You may also want to read this article to see how these oils stack up. I hope it helps. All oils are not the same and so you cannot use the same oil change inteval for these oils. The best judge of oil change intervals is you, and no one else. Anyone who drives their car with great attentiveness, will notice that their cars performance does change as the engine oil gets worn. and this change in performance will differ from one oil to another.


Oils Against Oils - Major Oil Brands go head-to-head on the dyno.

[coolieman1220]

i use Amsoil! thats some good stuff right there. forget about royal purple. The G35 gets 0w-30, bit too light for a 6 year old engine. but it does allow it to run harder. it does burn up a lot at high RPM's.

[G35COUPE]

i use Amsoil! thats some good stuff right there. forget about royal purple. The G35 gets 0w-30, bit too light for a 6 year old engine. but it does allow it to run harder. it does burn up a lot at high RPM's.

I wish I had the mullah to buy Amsoil---its way more expensive than Royal Purple and I understand oil change intervals can actually last as long as 10,000 miles or more. Is this right? The manual of the G35 specifies 5w-30. Of course, somewhere around 100,000 miles, its a good idea to switch to 10w-40

[drakkie]

I got this english spoken powerpoint on motor oils somewhere. Wish i could find it. It was a 4 hours long speech by some guy from Total, about 2 years ago. Voluntary to go to but very very educative. E-mailed my teacher but it'll take some time to reply i guess.