advantages of synthetic oil?

[BOXRPWR]

switching to Mobil 1 syn oil for the first time. I'm a few hundred miles shy of 35k. A buddy recommended getting 10W-30 instead of the factory recommended 5W-30. Supposed to resist thermal breakdown better. I am going to the track for two hard days of driving next weekend. Even though winter is approaching, we do live in So. Cal so that means the lowest temp will be like 40s in the morning and 70s during the day. No deep freeze issues around here.

Thoughts????

[crafty]

If I were where you are I would run 10-30 as well. The synthetic almost seems to light in warm weather.

I live in the snow belt and will run 5-30 in the winter and switch to 10-30 for the summer.

This is my opinion - after all I change everything else for the winter/summer

 

I say 5-7k between oil changes with any synthetic

[KTM 525]

I've been using Mobil1 0W40 for the last 5k miles. This car gets it's share of thrashings. I am at stage 2 the oil was changed yesterday. This oil saw a trip to the dragstrip and numerous dyno pulls at TDC. 2,900 miles on it and it looked/smelled pretty beat. I personally would not go beyond 3500 miles judging by what I saw come out. Far from a scientific oil analysis like some guys do but thats just what I took from it.

[rporter]

If I were where you are I would run 10-30 as well. The synthetic almost seems to light in warm weather.

I live in the snow belt and will run 5-30 in the winter and switch to 10-30 for the summer.

This is my opinion - after all I change everything else for the winter/summer

 

I say 5-7k between oil changes with any synthetic

 

+1

 

I go out to 7K, and never more than 7,500, just to stay under Subaru's recommendations (in case of any issue down the road).

 

I did run 0w-30 last winter, and will proably also do so this winter (and AutoZone has a sale on Syntec for $3.99!)

[GardenWeasel]

I'll wait until I hit 30K to switch to synthetic.

 

 

That's when I run out of free maintenace coupons.

[MDTURBO]

I would not do synth. Dyno oil is better for turbo seals. Unless it's specifically formulated for turbo cars, I wouldn't use it on a turbo car.

[PhilT]

If you add up the money you save by not using synth oil, you could buy an accessport !

[rporter]

When I do synth changes at 7-7.5K, and dino changes at 3-4K, and synth is 2x the cost, the oil cost is the same. it's cheaper for the synth, though, as it is one less filter change.

 

That's not the issue, the issue is the better durability of synthetic.

 

Synthetic has the same "seal swell" in it as dino oil, it is a non-issue for turbo seals. That is a story that won't die. When Mobil 1 first came out years ago, they did not put in the seal swell additive, and seals leaked. that was rectified way early on, and has not been an issue for many, many years. Turbo Porsches have had synthetic as a factory fill for years...I think those engineers know a thing or two. As I have heard, Evos also have synthetic as a factory fill.

[aldouse]

ok... here's a another question... i just switched to mobile1 on this most recent oil change (yesterday). now my question. it says i i can go up to 15000miles before next oil change, i plan at no more than 10k before change. so here it is... do i still have to change my filters at every 3k/3months? or not till that very long oil change?

[crafty]

This thread is all about opinion.

 

The fact that you do not have a turbo - IMO, Synthetic Oil is a waste of your money.

 

To answer your question, Change your filter at the same interval you believe you should change your oil.

[rporter]

ok... here's a another question... i just switched to mobile1 on this most recent oil change (yesterday). now my question. it says i i can go up to 15000miles before next oil change, i plan at no more than 10k before change. so here it is... do i still have to change my filters at every 3k/3months? or not till that very long oil change?

 

I wouldn't go that long, mainly because Subaru recommends changes NLT 7,500 miles, and you wouldn't want a warranty hassle down the road if you go longer than that (even though the oil will be fine).

 

Change the filter at the oil change. I agree with Crafty, I personally wouldn't bother with synthetic on normally aspirated (n/a) engine.

 

Having said that, I just put synthetic in my wife's '95 Del Sol. At 42K miles, I changed the oil at just under 3K mileage......and the last oil change was in October '03!! Needless to say, it doesn't get driven much!! I was buying oil for my car, and the synth was on sale, so I just went with it for hers. I didn't feel that it was a financial penalty when the next 3K oil change is 2-3 years down the road.

[melayout]

I would not do synth. Dyno oil is better for turbo seals. Unless it's specifically formulated for turbo cars, I wouldn't use it on a turbo car.

Switched to Mobil 1 5W-30 at @ 7500miles per the dealer's recommendation and since then consumption worsened till it got to about 1quart/700miles @ the 35000 mile marker. Dealer did an oil consumption test and after concluding it consumes too much, triaging turned out that the turbo seal was busted and it was letting oil into the intake side filling up the intercooler and everything. I just go the car back with a new turbo and they said to stick to dino.

 

Edit: Also like to add, that it also depends on one's driving. If you drive hard, IMO Mobil 1 30 weight oils will not holdup, go for a 40 wieght, at least that's what I'm getting from my "experiment", or try a renowned synthetic like Amsoil.

[rporter]

Switched to Mobil 1 5W-30 at @ 7500miles per the dealer's recommendation and since then consumption worsened till it got to about 1quart/700miles @ the 35000 mile marker. Dealer did an oil consumption test and after concluding it consumes too much, triaging turned out that the turbo seal was busted and it was letting oil into the intake side filling up the intercooler and everything. I just go the car back with a new turbo and they said to stick to dino.

 

Edit: Also like to add, that it also depends on one's driving. If you drive hard, IMO Mobil 1 30 weight oils will not holdup, go for a 40 wieght, at least that's what I'm getting from my "experiment", or try a renowned synthetic like Amsoil.

 

FWIW, at the dragstrip a couple of weeks ago, I added a quart of the 5w-30 Mobil 1 that I'm currently running (going to 0w-30 Syntec in a few weeks.....which I also ran last winter). That was at 24.2K. The oil was changed at 19.2K, and I had added exactly 1.5 qts over that 5K miles (the original 1/2-quart was left over from the oil change). For as hard as I drive my car, a quart every 3K miles is very acceptable to me. I went over to synthetic at the first oil change at 1,700 miles.

 

I don't want to get the "Amsoi Kool-Aid Drinkers" started (just finished one of those threads on another forum!!), but Amsol has nothing over other name synthetics.....except price.

[melayout]

rporter - Are you familiar with http://www.bobistheoilguy.com forums?

[rporter]

rporter - Are you familiar with http://www.bobistheoilguy.com forums?

 

Yes. I spent time out there in years past.....haven't done so in a couple of years. These "oil discussions" have been going on in forums for the last 10 years at least, and the same tired arguments ave made me lose interest.

[harrydog]

+1

 

 

I did run 0w-30 last winter, and will proably also do so this winter (and AutoZone has a sale on Syntec for $3.99!)

Castrol Syntec 0w30 (European Formula) is a really great oil. I used it in my WRX, even in the summer, and had no consumption issues at all and excellent wear numbers (based on oil analysis).

[Ed_T]

stay away from dino in a turbo engine

 

between the extra heat and hot spots, you'll run better and longer with full syn and did i mention much cleaner?

 

and you can change it every 7,500m without losing sleep over fried polymers and shearing

[thatwouldbegreat]

Way too many half truths and rumors about oil.

 

Most modern oils use better oil base stocks to meet the newer oil specifications.

 

These oil base stocks are often Group II or Group III which are highly processed conventional oil. These modern base stock have fewer impurities, less wax, have better physical properties like a higher viscosity index, and are increasingly similar to synthetic base stocks.

 

Many oils also contain some 'true synthetic' Group IV [ PAO ] or Group V [ Ester ] base stocks to further improve perfomance.

 

In addition, many synthetic oils use Group III severely hydrocracked oil and good additives and are priced as true synthetics but really are not.

 

Some of the biggest advantage of most synthetics are:

 

- uniform oil molecules,

 

-zero or low levels of impurities,

 

- better performance at extreme temperatures [ hot and cold ]

 

-superior additive packages,

 

-lower evaporation rates ar high temperatures,

 

-wider ambient temperature range for a given multi grade [ a 0W-30 or 0W-40 synthetic will be a better 'year round' fill than running 5W-30 dino in the winter and 10W-40 dino in the summer ]

 

-a synthetic can work well at longer oil change intervals for 'severe operation' and can be used up to the normal interval even during severe conditions like mountain roads, short trips, stop and go driving, extreme cold or heat, or towing.

 

-and a higher Viscosity Index which means that fewer polymeric additives are needed to make a multi grade oil.

 

Many conventional oils are closer than ever to the level of perfomance of synthetics, and often contain synthetics oil.

 

The quality and treat level of the additive package is as important as the base stock, so the formulation of a given oil is what matters.

 

Halvoline, Chevron Supreme, Conoco, Phillips Trop Arctic, Motorcraft, Castrol GTX, Pennzoil, Exxon Superflo are just some of the good inexpensive oils. All of these should work well for 3750 miles.

 

Mobil 1, Pennzoil Platinum, Redline, Amsoil, Valvoline Synpower, Motul are some of the good premium synthetics. All of these should work well for 7500 miles.

 

For modified or hard driven engines, especially turbo engines, synthetic should be better. Redline would be my choice if the engine is highly modified or driven on the race track occasionally.

 

For longer drain intervals 10,000 up to 15,000 miles... Mobil 1 Extended Performance or Amsoil should work well, and Redline should also do well up to 8,000 to 12,000 miles.

 

Any modern name brand oil with the proper viscosity and approvals will work well if you use the right oil change interval and factor in your driving environment and style.

 

I think it is perfectly fine to change to synthetic oil at the first oil change at 3000 to 5000 miles.

[06 Legacy GT]

who ever said it is right, many a board has gotten swamped by one weight versus another, let alone synthetic or even which synthetic.

 

Several things always surface however once you do countless hours of research.

Synthetics will last much longer and provide a higher level of protection. I have routinely changed my synthetic oil every 8,000 miles in my WRX for 4 years and will plan to do the same with my 06 Legacy GT. BTW, my Corvette Z06 monitors the oil change interval and it easily goes to 10,000 miles. You must change it however, at either 1 year or when the monitor life span goes to 0%, which ever comes first.

Secondly, the weight of the oil is not critical except in colder weather. Suffice it to say that the new Mobil 1 5W30 and Mobil 1 0W40 oils have almost identical viscosity's at 40 degrees Celsius however the 0w40 M1 offers better protection at 100C or above. So, it's your choice with M1 0W40 giving you a bit more protection at higher temps.

Finally, changing the filter is far more important than changing the oil, when using synthetics and going for longer oil change intervals.

 

Oh one more thing, as of later last year the new GF4 and/or SM rating was released, available almost everywhere as of this post. The GF3s and SLs are 2nd best now. The GF4 and SM oils offer even better viscosity stability with age, oxidation resistance and less detrimental effect on the catalytic converters. In fact the new longer converter warranty ( I believe it's 100K miles) is only honored if you use the GF4 or SM oils. It turns out it was cheaper to redesign the oil than redesign the converters.

 

As for when to switch, if you decide to do so, add the Corvette Z06 to the list of engines that come with synthetic (Mobil 1) from the factory. Break in it seems is no longer an issue with synthetics.

Want to play it safe. Wait till 1000 miles to conclude the Subaru stated break in procedure and then do what you want with oil type and viscosity.