anthrax144

3k miles? Why bother with synthetic then? Did you not see my post a few up that showed ACTUAL test results? 8,000 miles with plenty of life left. It's not just a "claim" when real life testing shows it to be true.

Not to mention, your statements about synthetic oil not being man-made is also false. It is not "refined more" as you claim. Is chemically altered to change it's properties. Yes, it comes from oil (petroleum) base but no amount of refining is going to make it "synthetic".

Seriously, don't go around misinforming people and making accusations about false claims when you don't know what you're talking about in the first place.

Slammer1

Easy there hard charger. I'm no idiot and I didn't make any accusations. If you disagree with my opinion or my maintenance routine, that's fine. Don't act like I'm trying to mis-inform my fellow members. The forum guidelines on respectful posts and responses would be a good read for you my friend. Read the following, copied and pasted from Mobil 1s website:

Synthetic Oil vs. Conventional Oils



There are two basic types of engine oil available:
Conventional mineral oil, the traditional engine oil and most widely used

Synthetic motor oil , which is steadily gaining popularity among auto manufacturers and consumers

(There are also synthetic blend motor oils, which are a blend of synthetic oils and conventional mineral oils. Synthetic blend motor oils are also sometimes called “semi-synthetics”.)

Both types of engine oil are made from crude oil that comes from the ground. The difference is that synthetic oils undergo numerous additional highly-advanced distilling, refining, and purification processes — and therefore are of a higher purity and quality than conventional mineral oils. This not only removes more impurities from the original crude, it also enables the engineering of the lubricant’s individual molecules to be uniform and consistent, tailored to meet the specific high-performance demands of modern engines. These customized molecules provide higher levels of protection and performance, even in extreme conditions.

The performance of synthetic motor oil is more robust, especially in terms of low-temperature pumpability, high-temperature stability, and protection against deposits. These attributes translate directly into less engine wear and longer engine life.

ISCjonny

iTrader: (7)

synthetic by definition already means...
- not natural
- prepared or made artificially

that being said... Synthetic motor oils are man made oils from the following classes of lubricants:

1. Polyalphaolefin (PAO) = American Petroleum Institute (API) Group IV base oil

2. Synthetic esters, etc. = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, etc.)

3. Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Shell, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high-quality mineral lubricating oil. In 2005, production of GTL (gas-to-liquid) Group III base stocks began, the best of which perform much like polyalphaolefin. Group III-base stocks are widely permitted to be marketed as synthetic motor oil with few exceptions where they are not allowed to be marketed as "synthetic" (for example, Germany).

Mobil1 synthetic oils fall under group 3 category. They have gone through a process that has turned crude oil to perform similar to group 1 synthetic lubricants. Thus in certain countries allowed to use the name synthetic, however in reality it is not a true synthetic.

http://en.wikipedia.org/wiki/Synthetic_oil

Kurtz

iTrader: (1)

I'd stay away from those mechanics.

The two are completely compatible, backward, forward, and even mixed together (which is what a synthetic blend sold in the store is).


But yeah, for normal street car driving there's 2 reasons to use synthetic and only the first matters to most:

1) Longer change intervals. If you change your oil way too often anyway (like very 3k miles) then by all means stick to conventional here, you'd just be wasting even more money with synthetic.

Used oil analysis on the 2IS shows that even on conventional it's generally fine with 7500-10k change intervals.... changing at 3k is literally pouring money down a drain. Even 5k is too often for this car... but 3k hasn't been valid advice for any car made in decades.


Running synthetic you should easily be able to run at least 15k between changes or more (though you'd wanna change the OEM filter at 7500).


(disclaimer- the above assumes normal driving conditions... if you're under severe duty conditions like excessive idling, only ever taking 5 minute trips, etc then use the cheapest stuff you can find and change every 3 months regardless of mileage)

As always UOA will tell you how long YOUR oil is good for in YOUR car under YOUR driving conditions... but I've never seen a single UOA of the many many that have been posted for the 2IS that disagree with the above advice.

2) Catastrophic oil loss. This is an edge case so shouldn't matter much-- but in theory if running synthetic and you have a massive loss of oil/pressure (I dunno, you forgot to put the drain plug back right or something) your engine won't be ruined quite as quickly, and you might have a chance to turn it off and save it. Again, this doesn't happen hardly ever to anyone, but does happen.

My0gr81

Kurt

Please add extreme cold climate start as an another reason why synthetic is better than mineral. Synthetic allows for the oil to remain liquid and perform as a lubricant better in those conditions. Even though most use a block heater overnight, there are are times where a car parked in -32 C (0 F) during the day may have issues starting, or lack of lubrication for the first or so minute after start.

Kurtz

iTrader: (1)

ah, you're right of course... been a while since I've lived in the great white north so it had slipped my mind, but yeah synthetic also offers better cold-flow characteristics, which is certainly a benefit to those who live where it gets rather cold.

minato

iTrader: (1)

the dealer uses 0w20 synthetic oil for oil changes, I also thought 0w20 only comes in synthetic and 0w20 was the recommended oil for the IS, so why are we still debating conventional oil?

Kurtz

iTrader: (1)

Lexus switched to synthetic oil as the standard fill in the IS250 in...2011 I think? All previous years came factory filled with conventional (generally 5W-30) oil.

For the IS350 they never switched to synthetic at all.

(at least in US cars, canada might be different).

udithadj

I requested synthetic for my CPO 2008 is350 on it's 1st oil change and the dealer charged me $22 and filled with 0w20 synthetic

Herofmine

I am using only syntetic, so which one is better for NY climate 5w30 or 0w20? For cold winters and hot summers?

Kurtz

iTrader: (1)

Not clear here... you mean he charged $22 extra? Above what initial cost, since he surely didn't give you synthetic for $22 total.

Either way unsure of your point, what you asked him for isn't the factory fill, nor what's recommended either in your owners manual or on the oil cap of your engine... the fact he was willing to take your money to put it in doesn't really mean anything...

udithadj

I had to pay $22 extra for synthetic oil since the first oil change for a CPO is free. shoud i take it back to the dealer for the correct oil ?

Noeh

iTrader: (3)

Absolutely unnecessary.

Kurtz

iTrader: (1)

Ah, ok, that makes sense... likely they put in 0W-20 because that was the synthetic they had to hand (since it's the factory fill on the 2011+ IS250, but not the 350).

And it should be fine in a 350 as well, just not the officially recommended weight... might be worth sending a sample off for UOA if you intend to keep using it for future oil changes though.

udithadj

should I change to5w20 or 5w30?, I run fully synthetic even on my wife's rav4 v6 (5w30) and my past cars (subaru impreza (5W30) & 95 3000GT (10W30))