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Discussion Starter #1
What are the advantages of synthetics over petro based oils?

1. greater thermal stability, less thermal breakdown
2. greater detergency or cleaning ability
3. can flow at very low temperatures
4. higher vaporization temperature
5. less shearing under temperature and load

Thermal stability is important to long life of the lubricant. Additives and the base stock used are primary determiners of a lubricants thermal stability. Even if you see your oil temp guage show some normal reading it's important to know that in the engine there are much hotter areas for the oil to contend with than where the temp probe is located. Within the bearings, temperatures can approach 300 degrees F., and at the rings perhaps 500+ degrees. Petro based oil breakdown at these temps is assured.

Detergency is important to help sweep the combustion contaminants from the engine interior into the oil filter. Higher detergency prevents any buildup of these contaminants on the steel surfaces in the oil channels, and oil flow areas. Keeping these areas clear is important since any buildups can break free to contaminate smaller passages in the engine. This is probably why some people assert it's not a good idea to run a synthetic after using a petro based oil since the synthetics detergency is so great it might wash out prior contaminant deposits and foul the passages.

Low flow capability is an obvious advantage. Oil gets to where it needs to go qiucker during cold start conditions or in very cold weather. Synthetics can flow down to perhaps -40 F. Petro based oils with their parrafin wax dont do nearly as well in this regard.

Petro based oils have a tendency to vaporize off at high temperatures, which of course results in the deposits of contaminants that were in the oil prior to vaporization. These contaminant particles now have the ability to adhere to the interior surfaces of the engine.

Viscosity is everything in an engine. Petro based oils, once subject to high temperatures and high stress will thin out from the heat , and shear under increasing loads in the bearings. The hydrodynamic oil film in the sleeve bearing area of the mains is compromised. It will thin out, and the internal bearing oil pressure will be less. If there is a lesser thickness oil film in the bearing it will be able to handle lesser and lesser loads before metal to metal contact is made, and the soft main bearing material undermined. In a mains type sleeve bearing there is a very interesting oil flow shape, a resevoir of oil if you will, within the clearance of the bearing journal and bore. As best as I can describe it, it is a teardrop shape, and the oil is dragged off this teardrop by the crank journal into the high pressure region where the max load is. if this thin film boundary lube point is undermined, the engine is toast. Oil that is no longer up to carrying its rated load will not be able to prevent that metal to metal contact.

How hard are you on your oil? Not an easy question since not much is readily available to give you clear indicators how your driving style or trip lngths affect lubricants. Generally , if you dont let the oil and engine temps stabilize during a drive, thats hard on a lube. Trips over 10 miles should get you to those temps, trips under 10 miles or so, are rather hard on lubricants. Usually , on those short trips, combustion moisture and acids are not dealt with effectively by burning them off, nor have the piston rings fully temped up and seated. We all know what happens when the rings arent doing an effective job of sealing on an 11.5:1 compression engine.

Contrast the car that get 12,000 miles a year of highway trips of 30-150 miles duration with another car that gets 12,000 miles a year of 10 mile jaunts, easy to see now.

How about when you start the car? Do you let it get to temp befor you drive first, or do you take off within 30-60 seconds. Give yourself a star if you drive off within 30-60 seconds and dont let it idle for a long time. Idling a car to awrm her up takes far too long to get to operating temperature and is also very hard on the oil for the prior reasons also. Get that car moving, and keep the revs down low until shes all warmed up.


Now to get to the meat of the matter and see whats what with those Group IV and V synthetic lubricants.

group IV:

IN a nutshell their manufactured from Polyalphaolefins, which are made from synthesizing hydrocarbons. They offer most but not all the benefits of a true synthetic. They lack in a true synthetics increased detergency and thermal stability, so they get some additive packages to to up thier performance in these areas. I do not refer to group IV based lubricants as true synthetics since they are still hydrocarbon based, even though man made. In this group , the additives usually give the different characteristics and performance differences in this group of lubricants. Amsoil and Mobil 1 are the two best known of the Group IV base stock lubricants. generally speaking, these oils will be appropriate for most peoples driving styles, and they should be changed at no greater intervals than perhaps 5000-6000 miles.

group V:

These are the true synthetics made from organic esters, not containing hydrocarbons at all. They have all the benefits listed at the top of this thread in abundance.

These oils usually do not require any additives, and that is the main reason they have such extended change intervals. Most oils need to be changed due to thier additive packs being depleted.

These oils are also very expensive, but a conservative change interval of 10,000 miles evens out the cost a bit. Some of us , myself included, change them out at 7500 miles just for the feel good factor.

By the way, even though you dont change the oil for extended miles, dont be confused , still change the filter at 3000 miles maximum. The synthetics deal with engine sludges and contaminants better than petro based oils, they do not prevent them from forming though, so you still have to filter them out.

I believe the best known brand name for this group is Redline.

The castrol we get from the BMW dealer is a Group IV based lubricant.

The Castrol Syntec you can buy at the local NAPPA ia Group III based oil.


group I - III based oils are just not applicable to our engines, forget about them.
 

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Re: Synthetics and my take on them in our cars.

Thank you for taking the time to share your knowledge, Pete. I suppose then that Castrol TWS 10w-60 would be classified as a Group IV lubricant? Which Group V oil do you run in "The Precious"?

Thanks.


:cheers:
 

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Re: Synthetics and my take on them in our cars.

Thanks Pete. I'm guessing that the "BMW High Performance Synthetic" oil belongs to Group IV?
 

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Re: Synthetics and my take on them in our cars.

Gents

According to the Swiss Castrol website, Castrol TWS Motorsport 10w-60 is a "full synthetic", meaning a either Grp IV or Grp V, and most likely a blend of the two. This stuff is not LL01 or LL98 rated, but it is the oil that BMW Motorsport uses in the Formula BMW engines and in the M3 GTR V8.

Informed opinion on this site and others is that Castrol High Performance Synthetic Oil 5w-30 is actually the same product as Castrol TXT Softec LL01, which is also "synthetic". TXT is probably a Grp IV base oil, presumably with a whale of an additive package so you can run it for 30,000KM, per the LL01 spec. A Grp III base oil fulfils LL98, but a sythetic base is REQUIRED for LL01.

In North America, a great oil available from the retail chain stores is German-made Castrol Syntec 0w-30, a Grp IV/Grp V blend that carries the LL01 rating as well. It appears to be the same as Castrol Formula SLX in Europe. It's the "thinner, long-life" version of TWS, and I understand that Audi uses it for racing.

Cheers
JJ
 

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Discussion Starter #5 (Edited)
Re: Synthetics and my take on them in our cars.

SchnelleM5,

Precious right now is running with Redline SAE 10W40 , a true synthetic with a polyol ester base stock. It meets API service class SL/SJ/SH/CD/CF.

The website for redline oil is redlineoil.com and has some very good reading to more fully investigate and understand the whole business about synthetics. You will probably feel very comfortable in alternate synthetic lubricant selections after reading and understanding the info on this web site.

Elevens,

Yes the BMW Synthetic is a Group IV base stock lubricant, with a synthetic hydrocarbon base stock.

jaj,

I was unaware that Castrol returned to using a synthetic base stock for Syntec oils. I do know that in 1997 they went from a group IV base stock to a Group III base stock. Thats about the same time they ran afoul of some advertising claims that were a bit suspect. I seem to remember some discussion about the oils Sodium Hydroxide additive problems. Seems that they could not get the long life of a true synthetic since the Sodium Hydroxide depleted long before the extemded mileage oil changes could be reached, causing some acid problems. I'll check this out as my memory might be misleading me here, but thats what I recall.
If its true that they have gone back to Group IV base stocks thats refreshing news indeed. Or were you refering exclusively to the 0W-30 lubricant?
 

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Discussion Starter #6 (Edited)
Re: Synthetics and my take on them in our cars.

I found some more information about Syntec.

It appears that indeed Syntec was altered in 1997 to a Group III base stock oil from a Group IV. However, thru some ruling by the NARC (national advertising review council), Castrol has been allowed to market this oil as a synthetic. NARC based its decision on the process of Syntecs refining, it appears to undergo further refining than regular petro oils.

The problem with Syntec was in fact its inability to support long drain intervals. The reason for this was the sodium hydroxide issue as previously mentioned.

The ruling by he NARC did cause Mobil to file objections with them with respect to some advertising claims made by castrol which were technically inaccurate. Mobil was not a happy camper about all of this.

I also went on castrols website and could not find any statement as to what they use for a base stock for this lubricant. They do however advertise it as a synthetic. From the available data sheets on that site it meets most if not all the requirments of auto manufacturers, however I did not see any claims about drain intervals. Just dont expect to get the life from syntec that you would from say redline or mobil 1.

If anyone has more detailed info I would appreciate your input.

By the way, the further refining process syntec goes through is something clled hydroisomerization. Does anyone know what the heck that process is?
 

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Re: Synthetics and my take on them in our cars.

Pete

From what I can see in researching motor oil, lubrication engineers use Viscosity Index as a proxy for purity in base oils (not finished products). Hence, low VI oils are around 100 and are "Grp I". High VI oils are higher group numbers, and Grp III and Grp IV have similar ranges of VI - but Grp IV is made by isomerizing ethylene gas, and Grp III is made by isomerizing petroleum crude oil. Grp IV contains the least amount of imperfections, and hence is the most resistant to oxidation and sludge formation. Of course, that's the base - toss in an additive package with a Grp I carrier oil, and all that purity is for nought!

In North America, Grp III can be called "synthetic" and there are some excellent oils based on it, like Castrol Syntec. The biggest difference for actual use is that Grp IV-based oils will last longer than Grp III. The differences are not dramatic (BMW in the LL98 spec allows Grp III for 25,000 KM use, while LL01 requires a full synthetic base and allows its use for 30,000 KM).

Then there's the odd man out -- German-made Syntec 0w-30 (and there is also a North American made Syntec 0w-30 out there) appears to be repackaged European Formula SLX, which is referred to as "Vollsynthese", or "Full Synthetic" in Germany. The only oils that Castrol makes that they call Vollsynthese are SLX, Formula RS, and TWS. The rest are "highly processed petroleum oils", or Grp III. SLX passes BMW LL01, so it's the real deal. So does Mobil 1 0w-40 by the way - but it's the only Mobil product that meets LL-anything!

Cheers
JJ
 

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Re: Synthetics and my take on them in our cars.

Hello Pete,

Thanks for the information. BMW recommends an oil change at least once a year. Since I put about 2K on the M5 per year, what is happening to the oil to require a change? I'm assuming that this doesn't happen if the oil is kept in its sealed container. What's the shelf life of it?

Thanks for the education, Philip
 

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Re: Synthetics and my take on them in our cars.

Pete,

Good discussion here. Let me try and understand what the implications are from your dicussion above.

Are the oils that BMW reccommends, ie. Castrol 5W-30 synthetic good for 7500 mile oil change intervals or 5000 mile changes?

Thanks,

Mark
 

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Discussion Starter #10
Re: Synthetics and my take on them in our cars.

MAH
Since the oil BMW recommends is the Group IV synthetic it should be fine to use it for 7500 miles. If your driving conditioins are more severe than what might be considered normal it would be a good idea to maybe change the filter a bit more frequently. I would still change the Group IV oils at 5000 mile intervals, but thats just me. I change the filter at 2500 mile intervals.

Philip
I have no idea why BMW recommends to change the oil once a year, other than to say , at least you get the car in for a look see once a year. On the other hand, synthetics are not invincible. BMW probably assumes a certain amount of starts take place in a years time. If the trips are short, thats hard even on the synthetics, so best to err on the side of caution and just have it replaced once a year even if you dont put any miles on the car. I can envision also that they might have some concern about water condensation issues over a years time, but thats just speculation.


jaj
I am constantly amazed at how many different ways the car industry has to describe or quantify the quality and selection of oils. Its much easier in the world of industrial lubricants.
I thought I'd give this Redline 10W-40 a try now that its it colder here and see if I can tell any differences. It's kind of hard to determine any gains so far, not even sure if there will be any. Mileage still seems to be the same so probably not going to be able to quanitify anything noticable.
One thing I did notice, and I"m not sure if its a fluke or what, but I have had it in now for 1000 miles and I havent noticed very much oil consumption yet. I found that rather odd, and cannot come to a reasonable explanation for it as yet. Maybe that will change with a bit more spirited driving.

We will see.
 

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Re: Synthetics and my take on them in our cars.

Do you guys know which of the popular fully synthetic brands (Mobil 1, Redline, etc.) would meet BMW specifications while one's car is under warranty? I'd like more protection than the BMW oil provides, and my Blackstone lab report came out indicating possible engine wear :( so I may want to switch if I do not risk warranty denial. So far I have stuck with BMW oil and filter and had the oil changed at no more than 4000 mile intervals, and usually less.
 

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Re: Synthetics and my take on them in our cars.

Redshift

The mass-market brands (by marketing style, not by quality - this is NOT a slam) that meet LL01 are few and far between. Basically, for any oil, if it doesn't say "meets BMW LL98 or LL01" on the bottle, then regardless of what the advertising and the website might say, DON'T USE IT!

There are two mass market oils that meet the spec: Mobil 1 0w-40 is approved for BMW LL01 and so is German-made Castrol Syntec 0w-30. If you want to use something thicker, then BMW's Castrol TWS Motorsport 10w-60 is about all that's left.

Redline, Amsoil, etc are very good products, but I'm not aware if any of them have either BMW LL rating, and that could be bad if you have an engine problem that prompts BMW to look at the oil.

If you're willing to use BMW LL-98 oil, then your choice broadens considerably! Castrol Syntec 5w-40, Pennzoil European Formula 5w-40, Quaker State European Formula 5w-40, and a host of others meet LL98.

Cheers
JJ
 

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Re: Synthetics and my take on them in our cars.

JJ, thank you for the excellent and concise reply. I take it the factory requires LL01 specification for oil if warranty coverage is to be retained? Is LL98 acceptable for warranty coverage or only LL01?

Along the same lines, for DE events, would Mobil 1 0W-40 be acceptable or would I be better off using the standard BMW 5W-30?
 

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Re: Synthetics and my take on them in our cars.

Redshift

I use TWS 10w-60 for DE events. It has far higher viscosity at high temperature than any of the others do.

Most of the "regular" LL01 oils are intended for daily driving with maximum fuel economy, and they have as low a "High Temperature/High Shear" viscosity as they are allowed to have - in this case it's 3.6 Cp at 150 degrees C. The TWS is 5.8,Cp at 150 degrees, so it has around 60% higher viscosity under stress. Both the M1 0w-40 and the Syntec 0w-30 have HTHS of 3.6, as does the BMW HPSO 5w-30. They're functionally interchangeable,although you might have lower oil consumption with one than another.

As for the LL98 or LL01 question, the only practical difference is that BMW certifies one for 25,000KM (LL98) oil change intervals, and the other (LL01) for 30,000KM. Needless to say, if you change oil at half the interval of the green lights, either rating will work fine. I doubt that BMW has a test to tell which oil is which - they rely on you to prove that it's LL rated if it has a different spectral signature than their own products.

If you don't care about the warranty (a nice world to be able to be in!) then Redline, Motul, Lubro-moly and others make excellent racing oils with very high ester content. These are not usually tested to the "commercial" specs like LL01, but they have operational benefits that support stressful situations well.

Cheers
JJ
 

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Discussion Starter #15
Re: Synthetics and my take on them in our cars.

Valvoline Maxlife synthetic is LL01 approved.
Motul Specific LL01 5W-30 is LL01 approved.
a few elf lubricant products are also LL01 approved.


Fuchs-Silkolene PRO S and PRO R as far as I have come to learn today from a lubrication engineer vendor of mine are at the top of the heap as far as synthetic ester based oils are concerned. I respect this guys opinions and he has always come through with very informed answers. Apparently ester based lubs are surface active ( electrostatically attracted to metal surfaces), and help reduce wear and friction by that phenomena.

Redshift , this might interest you.

Pro S 10W-50, 5W-40
A fully synthetic high performance engine oil that provides optimum protection for extended engine life and reliability. It exceeds the performance requirements of virtually all engine manufacturers. Combines exceptional anti-wear performance and outstanding high temperature protection with excellent cold start characteristics. Suitable for use in turbocharged and normally aspirated, diesel and petrol engines to ensure continued maximum fuel economy and reduced emissions. API SJ, SL, CL, ACEA A3, B3, BMW & MERCEDES

Pro R 15W-50
Pro R 15W-50 is an ester synthetic lubricant with advanced friction reduction chemistry developed to provide outstanding protection for performance and competition engines, both normally aspirated and turbocharged. Highly stressed power units running lead-free, low lead or conventional fuels benefit from the extra protection of Pro R15W-50. Testbed and racing experience shows significant increase in power output making Pro R 15W-50 ideal for motor sport, competition and fast road applications. API SF, SG, SH & SJ
 

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Re: Synthetics and my take on them in our cars.

Pete said:
Valvoline Maxlife synthetic is LL01 approved.
Motul Specific LL01 5W-30 is LL01 approved.
a few elf lubricant products are also LL01 approved.


Fuchs-Silkolene PRO S and PRO R as far as I have come to learn today from a lubrication engineer vendor of mine are at the top of the heap as far as synthetic ester based oils are concerned. I respect this guys opinions and he has always come through with very informed answers. Apparently ester based lubs are surface active ( electrostatically attracted to metal surfaces), and help reduce wear and friction by that phenomena.

Redshift , this might interest you.

Pro S 10W-50, 5W-40
A fully synthetic high performance engine oil that provides optimum protection for extended engine life and reliability. It exceeds the performance requirements of virtually all engine manufacturers. Combines exceptional anti-wear performance and outstanding high temperature protection with excellent cold start characteristics. Suitable for use in turbocharged and normally aspirated, diesel and petrol engines to ensure continued maximum fuel economy and reduced emissions. API SJ, SL, CL, ACEA A3, B3, BMW & MERCEDES

Pro R 15W-50
Pro R 15W-50 is an ester synthetic lubricant with advanced friction reduction chemistry developed to provide outstanding protection for performance and competition engines, both normally aspirated and turbocharged. Highly stressed power units running lead-free, low lead or conventional fuels benefit from the extra protection of Pro R15W-50. Testbed and racing experience shows significant increase in power output making Pro R 15W-50 ideal for motor sport, competition and fast road applications. API SF, SG, SH & SJ
Pete,

Thank you for the oil education. The two lines that you have listed above I have not seen before. Would you happen to know where they might be available and what the cost may be?

Thanks again for the info,

Mark
 

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Re: Synthetics and my take on them in our cars.

Pete,

Last winter, I was seated next to a retired oil co R&D person (at a BMW fuction, natch) and if I remember correctly he told me that the car manufacturers sometimes work with an oil manufacturer to create a specific additive package for the oil used in a vehicle--not knowing enough about this topic, I just wondered how much the additive packages vary amoung the above mentioned oils and just how important it is for us to stick with one recommended by BMW?

Thanks and thanks for all this info!!

And I can say my old '88 Mustang has survived the switch to Mobil 1 many yrs back.

Anita
 

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Discussion Starter #18
Re: Synthetics and my take on them in our cars.

MAH,

I only found out about the SIlkolene yesterday so I have no sources for it yet. I do know that the firm sells in the US though, maybe a webb search will give you some hits. I imagine it's not inexpensive. Probably in the 12-15 dollars / liter or so.

The Redline I am using presently was a gratuity from the same lube engineer that gave me the heads up on Silkolene. LMAO, I gave his name to one of my Ski Resort customers and he was able to get them to fill all their lift gearboxes with synthetic gear oil before the season. He was pleased to say the least.

Anita,

Oil additive packages and their actual ingredients and amounts are somewhat propriety information. OIl certifications do tend to even out the playing field though.

As a general rule its relatively safe to say that if you are going to switch to a non oem approved oil, always go up in quality never shift laterally or go down the scale.


It should be noted that it is a waste of money to use these ester based oils if you change your oil frequently as I do, unless you are experiencing wear problems for some unknown reason. I believe jaj pointed this out in one of his fine posts.

To be quite honest about it Anita, there isnt really a good reason to switch to a non oem oil other than the belief that there should have been improvements to oils in the time you have owned the car. If you run your car hard or track it frequently maybe an ester based oil will give a bit of insurance or peace of mind.

A more important consideration in my mind than choosing to run a Group IV or V oil is changing the viscosity of the oil. I would tend to prefer to use the factories numbers here, or as close as possible to them rather than change to something substantially different from OEM recommended. The Silkolene 5W-50 is close enough to 10W-60 for me, even the Redline 10W-40 is ok for me right now, I would not try a 5W-30 for my 2000 M5.

Have a nice day everyone. Looks like another pretty one in Colorado.
 

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Re: Synthetics and my take on them in our cars.

I'm interested in switching oils because of an alarming (to me) buildup of carbon on the heads and pistons at about 30K miles, half of which were high-speed long-trip highway miles. This, despite using the best gas as well as a fuel system cleaner (not a FI cleaner but the strongest version of Techron, claimed to reduce or eliminate combustion chamber deposits) prior to each oil change. I can only conclude that the oil is the culprit.

I have a high-oil-consumption 2000 motor that typically sees an oil change around 5-6K miles. My shop says the kinds of deposits I'm concerned about are quite normal in BMWs but I have to believe that there's a better mousetrap waiting out there in the true ester-based synthetics. I'm hunting some Silkolene Pro S 10W-50 down as we speak...
 

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Discussion Starter #20
Re: Synthetics and my take on them in our cars.

Well , today I had to add a bottle of the redline to the car.

It appears that I am getting about the same mileage with the Redline 10W-40 as I previously did with the factory Castrol TWS 10W-60. That's what my data is telling me anyway, right around 1800 miles/bottle. My gas mileage does not seem to have changed very much at all, still about 14.9 mpg without the sport button engaged, and somewhere in the vicinity of 13.9 mpg with sport mode on. I should also not that for my car at least, ambient temperature does not seem to make a difference in oil consumption. At least not with the temperatures I drive the car in. Most of my driving is typical suburban traffic light driving.

I think after the winter I will be trying the Silkolene 10W-50 as well. That puts me just a tad closer to the factory recommemded viscosity range. Now that I know of something closer to factory spec in a ester based lubricant I will try it. Maybe I can get closer to 2000 miles/ bottle.

Since the car has had some work done to it in the recent past I also grabbed a 2 ounce sample of the oil for testing. Should get the results from that back in a week or so. I have to say, the oil did not look bad at all.

I've read a lot of information and asked a few questions about our cars oil consumption. The general consensus seems to be that our engines have some designed in clearances due to its high performance nature. Depending on who was talking it seems that 1500 to 2000 miles/bottle of oil consumption is not out of line.

My car has recently had quite a bit of work done to it under warranty. It had to do with the timing. Part of that work involved replacing the valves and lifters, as well as the vanos banks, and some other things. All the updates and fixes were also performed, so I basically have a new top end on the engine. This should give my data a nice solid foundation. It is interesting to note that all this work did not substantially improve my consumption.
 
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