IS that what you used on your Rogue?

I use Castrol 0W30 (Made in Germany) a.k.a "GC" on all my vehicles. It works well on many vehicles requiring 5W30 weight oil. The 0 part means the oil is slightly thinner when cold... a plus for cold winters. As for 30, this oil is actually towards the 40 weight end of the scale. This heavier weight has helped many who have had issues with valve noise, etc. Extensive oil testing has been done with GC and it produces some of the lowest wear levels of any sythentic oil. GC is a true group IV synthetic and can be run for longer periods between oil changes. With proper oil testing (you can get sample kits from Blackstone Labs), you can easily extend your change intervals to 10,000km (6,000mi). This is what I do.

You can purchase GC at Autozone (US), and PartSource & Wal-Mart in Canada.

For oil filters, I use NAPA Gold. This is a very good filter made by WIX and IMHO is better than recent OEM Nissan filters in terms of construction. OEM Nissan filters would be my second choice.

Actually I plan to do my first oil change this weekend.

I plan to cut open the original filter and 1 year old Nissan filter just to see what I've got. The Nissan filters in question have cardboard end caps on the filter media as opposed to the metal caps! This does not affect all Nissan filters, but it's impossible to tell without opening the filter can.

BTW, there are 2 filter models:

15208-65F00 (same as NAPA 1365) - OEM Rogue filter. This shorter filter is used on some models for space reasons.15208-9E000 (same as NAPA 1356) - This is slightly longer than the 65F00 and is found on some other Nissan models including the Titan, Maxima, Pathfinder, 02-06 Altima, etc.

Both of these filters should fit, and I plan on installing the longer 9E000 to confirm this.

The NAPA Gold filter features the same anti-drainback and pressure bypass valves as OEM. The main differences are:

- All metal construction, no cardboard.- Pressure bypass is located at the bottom of the filter near the threads as opposed to the top of the filter media where oil can pickup dirt from the filter and recirculated back into the engine.

philipa_240sx,

Good call on the GC, do you plan on doing oil analysis on your Rogue? I'm about to post the latest on mine, it's been quick to break in and wears like a champ. I'm definately impressed with the QR25DE so far!

I just installed Schaeffer's Supreme 7000 and a Pure One for a 7500 mile run, eager to see how it looks.

Glad to see you are a moderator, I've enjoyed your posts. Thanks!

REDDOG

Forgot to mention I cut the factory filter when I changed it and it had the cardboard endcaps, as you described.

REDDOG wrote:Forgot to mention I cut the factory filter when I changed it and it had the cardboard endcaps, as you described.

Doh! Now I'm also gonna buy a new filter from the dealer just to see! I cut open a new 1yr. old filter and it has metal caps.

I cut the OEM filter open after my oil change. Definitely cardboard end caps. It also has a black anti-drainback valve as opposed to the pink colored of my older 9E000 filter. I will post pics shortly.

I tried both the longer 9E000 and NAPA 1356 filter and it fits no problem. The filter is 3/4" longer in length and gives you correspondingly more filter surface area which doesn't hurt.

Quote »I'm definately impressed with the QR25DE so far![/quote] Nissan has made some changes from the previous gen. No more dual runner with thier troublesome butterfly valves, different balancer system, increased compression ratio, resin intake manifold (does not conduct heat and is much smoother in the inside), and resin valve cover for less noise.

Oil Filter Photos:

New 9E000 purchased 1.5 yrs ago. This is like the original Nissan filters from a few years ago. Notice the pink anti-drainback valve. Due to age, I can no longer guarantee that newer filters of the same model have not gone to cardboard end caps as well.



OEM 65FC0B original factory filter. Notice the cardboard end caps and a black anti-drainback valve. Also notice the wider spaced holes in the metal tube inside the filter. These features might be the telltale indication you have the newer filter.



Now, the cardboard end caps do not mean the OEM filters will imminently fail. The filter proabably works just as well. However, I feel more comfortable with the sturdy metal construction of the old filters or the NAPA gold filters. I've installed a NAPA Gold 1356 filter. This filter looks much more like the good OEM 9E000 with the metal caps.

philipa_240sx wrote:Oil Filter Photos:

New 9E000 purchased 1.5 yrs ago. This is like the original Nissan filters from a few years ago. Notice the pink anti-drainback valve. Due to age, I can no longer guarantee that newer filters of the same model have not gone to cardboard end caps as well.



OEM 65FC0B original factory filter. Notice the cardboard end caps and a black anti-drainback valve. Also notice the wider spaced holes in the metal tube inside the filter. These features might be the telltale indication you have the newer filter.



Now, the cardboard end caps do not mean the OEM filters will imminently fail. The filter proabably works just as well. However, I feel more comfortable with the sturdy metal construction of the old filters or the NAPA gold filters. I've installed a NAPA Gold 1356 filter. This filter looks much more like the good OEM 9E000 with the metal caps.

Is Fram making Nissan filters now?? This looks like a cut away from a Fram oil filter I saw about a year ago. They are garbage...

The research done before shows Tough guard from Fram is good, don't go with Extra Guard. I am going to try OEM at next oil change, but don't know go with 65 or 9E, probably they are both using cardboard end. By the way, how big is the difference for their price?

The 9E000 fits no problem. However either will work just fine. I use the longer 9E000 equivalent: NAPA Gold 1356.

I don't believe there is much difference in price between the Nissan filters. The NAPA gold is about the same price as OEM... approx $10 CDN.

I still don't like Fram filters, regardless of model.

I'd like switch to full synthetic oil, will 15208-65F00 be fine for the 7500 mi interval?

If you are planning those kind of OCI's (oil change intervals), at least get the NAPA Gold filter #1365 which is an exact replacement. Personally, I would not use the OEM filters for extended OCI's.

Beagle_Hauler wrote: Am just a few hundred miles from my first oil change and am willing to try synthetic oil. I have never used synthetic in my other cars, but have always heard good things. Am curious if anyone here has filled up with synthetic oil yet and have noticed any changes. I understand older vehicles have oil seals that are not designed for synthetic oil and they breakdown and leak, but our Rogue's engines should be new enough that they have seals that resist both conventional and synthetic oil.

If no one has done it yet, I had BLACKSTONE LABS run a oil test on my first change.Natually expected high values for moly and silica(Ring breakin and cast sand.)It tested very nice.

FACTORY OIL USED Silkolene synthetic 0w-20..

Yes, its a fact now that Rogues come with synthetic oil right from the factory

mstrmstr wrote:
If no one has done it yet, I had BLACKSTONE LABS run a oil test on my first change.Natually expected high values for moly and silica(Ring breakin and cast sand.)It tested very nice.

FACTORY OIL USED Silkolene synthetic 0w-20..

Yes, its a fact now that Rogues come with synthetic oil right from the factory

Are you saying that Rogues are coming with syn. 0w20 or 5w30?? Do you know what brand?? My owners manual only says to use 5w30. I am going to my dealer for my 1 year service and I am going to ask that question...

I changed over to synthetic at 2100 miles. I have used synthetic oil in all my cars and trucks since 1992, and have never had any issues. I use a 5W-30 full synthetic. I will probably change the oil sometime this month so I have a fresh load for the winter.Thanks for the number of the alternate larger filter. I have always tried to use a filter larger than stock just to get that "little bit extra" filter capacity.

wbloomfield wrote:
Are you saying that Rogues are coming with syn. 0w20 or 5w30?? Do you know what brand?? My owners manual only says to use 5w30. I am going to my dealer for my 1 year service and I am going to ask that question...

Yes the Rogue hits the streets with a initial belly full of synthetic break in oil.

MFG is Silkolene(not common in the US) weight is 0w-20 it is formulated with very high detergents and is very thin which allows fast drainback and the ability to flush those initial contaminants into the oil pan where the filter can take them out.

In my opinion the first oil change should be over 1000 miles but I don't think 3750 should be the target until AFTER the first one. I believe the breakin oil need a bit of mileage to do its work. 1000-2000 sounds better and then change to your favorite brand of operating lubricant.

If you plan on extended oil changes you better get at least one lab test done to be sure your not defeating your purpose and running past the oils protective life. The big rigs run lab often because their livelihood depends on their engine. For us average mileage drivers its the peace of mind.

At change interval the manual likes 5w-30

AT our local WalMart name brand synthetics in 5 quart containers run $17.49 usd.. only three dollars more than the jurassic stuff.

Silkolene FYI if you never hear of it.. used a lot in snomobiles/motorcycle and other high stress engines. Silkolene - from a adSilkolene (owned by Fuchs) has one of the world's largest ranges of specialist car and motorcycle lubricants, developed on the race track to ensure ultimate performance and protection. In motorcycle racing, the brand is the first choice of factory teams such as Honda, Kawasaki and Suzuki.

Modified by mstrmstr at 10:18 PM 10/2/2008
Modified by mstrmstr at 10:41 PM 10/2/2008

mstrmstr wrote:Yes the Rogue hits the streets with a initial belly full of synthetic break in oil.

MFG is Silkolene(not common in the US) weight is 0w-20 it is formulated with very high detergents and is very thin which allows fast drainback and the ability to flush those initial contaminants into the oil pan where the filter can take them out.

In my opinion the first oil change should be over 1000 miles but I don't think 3750 should be the target until AFTER the first one. I believe the breakin oil need a bit of mileage to do its work. 1000-2000 sounds better and then change to your favorite brand of operating lubricant.

If the Rogue factory Fill is this special, I don't understand why not leaving it in the crankcase as long as prescribed.

As you can see on my oil analysis below, the TBN is still high at 3500 miles, so no worry (don't bother with the fuel, I sampled it badly after it sits all night).

I thought only Honda uses special break in oil, but seems Nissan does it too, so use it to its full potential, your car will thank you.

Hi Pescakl1,

Your testing service is a good one. Recommended by Amsoil.

Its just my preference to believe the engine is fully broke in at 1000-1500.Changing get the crap filled filter changed...

I noticed on your report that the sump capacity was listed at six yet the Rogue pan capacity is about 4.5 quarts.. yours must be liters?

Your viscosity is LOW even with a ok tbn(detergent/additives level) this is a result of the fuel in the oil. I run lab every other change on my engines.. every change on my farm equipment due to the harsh running environment.My last bog tractor cost 225,000 us USED.. when rings/bearings etc are going bad, I know before engine failure by doing the lab..cheap in that respect.

It's just a matter of personal preference and peace of mind.

report reading legend

Gas/Diesel Engines

Elements are quantified in the oil at part per million levels (PPM). This list shows the most common sources of the elements in a gasoline or diesel engine oil.

TBN is a comparison between virgin and used oils, relating to remaining additives. Aluminum: Pistons, bearings, cases (heads & blocks).Chromium: Rings, a trace element in steel.Iron: Cylinders, rotating shafts, the valve train, and any steel part sharing the oil.Copper: Brass or bronze parts, copper bushings, bearings, oil coolers, also an additive in some gasoline engine oils.Lead: Bearings.Tin: Bearings, bronze parts, piston coatings.Molybdenum: Anti-wear additive, coating on some new rings(washes off as break-in occurs).Nickel: Trace element in steel.Manganese: Trace element, additive in gasoline.Silver: Trace element.Titanium: Trace element.Potassium: Antifreeze inhibitor, additive in some oil types.Boron: Detergent/dispersant additive, antifreeze inhibitors.Silicon: Airborne dirt, sealers, gaskets, antifreeze inhibitors.Sodium: Antifreeze inhibitors, additive in some gasoline engine oils.Calcium: Detergent/dispersant additive.Magnesium: Detergent/dispersant additive.Phosphorus: Anti-wear additive.Zinc: Anti-wear additive.Barium: Detergent/dispersant additive. Physical properties: Viscosity, flashpoint, % fuel and antifreeze, % water and insolubles are all measured in gasoline and diesel engine oils. If fuel is present in the oil, the viscosity and flashpoint will often be lower than what was stated in the "Should be" line. Insolubles are solid material that is centrifuged out of the oil. They are typically free carbon from the oxidation of the oil itself, along with blow-by past the rings.


Modified by mstrmstr at 10:08 AM 10/3/2008

mstrmstr wrote:I noticed on your report that the sump capacity was listed at six yet the Rogue pan capacity is about 4.5 quarts.. yours must be liters?

Your viscosity is LOW even with a ok tbn(detergent/additives level) this is a result of the fuel in the oil. I run lab every other change on my engines.. every change on my farm equipment due to the harsh running environment.My last bog tractor cost 225,000 us USED.. when rings/bearings etc are going bad, I know before engine failure by doing the lab..cheap in that respect.

The problem with OAI lab is they don't really read the information you send with the sample and later ask:" Please provide unit model number as we may compare data to the proper standard for this units"

I am quite sure I give all the correct information as I know the quantity of oil I poured in and that I checked on the owner manual before to be sure to have enough oil to do my oil change, so once again for OAI lab:

Viscosity is indicated as low as I wrote them the oil was 5w30 (what the dealer told me ) but at 8.7 it is a xw20 oil as you said ( and the fuel dilution helped to keep it low).

Knowing the TBN was still that high, I would have kept the oil longer as Oxidation and Nitration level are still low. Some may profit from my mistake.

As contrary as you, I have learnt from someone which is in engine for years and has close contact with ExxonMobil engineers that it is better to keep the factory oil for the length of the recommended OCI.In fact, for those who do change their oil at 300 miles, then 1000, then 3000, and then do the recommended OCIs, it could be detrimental to the engine to do that instead of keeping the factory fill for the whole recommended OCI.

By curiosity, who told you what was the factory fill of the Rogue?

mstrmstr wrote: Aluminum: Pistons, bearings, cases (heads & blocks).Chromium: Rings, a trace element in steel.Iron: Cylinders, rotating shafts, the valve train, and any steel part sharing the oil.Copper: Brass or bronze parts, copper bushings, bearings, oil coolers, also an additive in some gasoline engine oils.Lead: Bearings.Tin: Bearings, bronze parts, piston coatings.Molybdenum: Anti-wear additive, coating on some new rings(washes off as break-in occurs).Nickel: Trace element in steel.Manganese: Trace element, additive in gasoline.Silver: Trace element.Titanium: Trace element.Potassium: Antifreeze inhibitor, additive in some oil types.Boron: Detergent/dispersant additive, antifreeze inhibitors.Silicon: Airborne dirt, sealers, gaskets, antifreeze inhibitors.Sodium: Antifreeze inhibitors, additive in some gasoline engine oils.Calcium: Detergent/dispersant additive.Magnesium: Detergent/dispersant additive.Phosphorus: Anti-wear additive.Zinc: Anti-wear additive.Barium: Detergent/dispersant additive.

This information is for engines in general or is it specific to our engine, the QR25DE?

Common automotive gasoline engine oil lab findings

Aluminum: Pistons, bearings, cases (heads & blocks).Chromium: Rings, a trace element in steel.Iron: Cylinders, rotating shafts, the valve train, and any steel part sharing the oil.Copper: Brass or bronze parts, copper bushings, bearings, oil coolers, also an additive in some gasoline engine oils.Lead: Bearings.Tin: Bearings, bronze parts, piston coatings.Molybdenum: Anti-wear additive, coating on some new rings(washes off as break-in occurs).Nickel: Trace element in steel.Manganese: Trace element, additive in gasoline.Silver: Trace element.Titanium: Trace element.Potassium: Antifreeze inhibitor, additive in some oil types.Boron: Detergent/dispersant additive, antifreeze inhibitors.Silicon: Airborne dirt, sealers, gaskets, antifreeze inhibitors.Sodium: Antifreeze inhibitors, additive in some gasoline engine oils.Calcium: Detergent/dispersant additive.Magnesium: Detergent/dispersant additive.Phosphorus: Anti-wear additive.Zinc: Anti-wear additive.Barium: Detergent/dispersant additive.

This information is for engines in general or is it specific to our engine, the QR25DE?

Answer, general information for automotive gasoline engines

My Lab(Blackstone) first specifically identified the oil type and grade.I first called and was told the oils carry a identifier.I then called the magic number to Nissan Consumer Affairs and got straight dope there after a couple of transfers. All Nissans hit the streets new with synthetic. One other cool note they gave me was a "breakin" period really is based on engine run time and not on mileage yet they tell us 3750 miles so as not to confuse the average owner.Of course almost everything on my farm equipment is base on the engine hours clock.

I keep my rolling stock roughly a decade so I'm cost aware but not penny wise/pound foolish.

It's a nice thing to know the guys in Fenton,MO are really listening to the consumers now, more than ever before.

I changed mine today (Rogue 2008) at 1871 miles to Mobil 1® and I ride about 50 miles round trip to my workplace and I found the car response a lot better and somewhat quieter.

I'm on my 4th oil change already using Castrol Syntec 0W30 (Made in Germany label on back) and a Napa Gold #1356 filter. It seems to be running well, but I have to send my sample in for analysis.

For those interested in extended intervals, here is my second and third oil analysis (second is at the beginning of the service to know with what I started with, third one at the end).

As you can see, with about 7500 miles in five and a half months, wear is minimum and at 17.331kms (about 11.000 miles), the car is nicely breaking in.

Extra silicon is from the engine and does not wear it (it was 145 on the first analysis and should be down again next time), and I don't know why they flagged the nitration level which is not that high.

Oil was Valvoline Synpower 5w30 and with the TBN still above 3, I could probably have gone a little bit longer. Good oil for the summer season.Now I am running PP 5w30 for the next 6 months (will probably not be able to do the 7500 miles limit).

Changed my AWD Rogue over to Amsoil (everything except CVT) as soon as I got it home (50 miles on it). Now I am at 13000 miles. The engine broke in beautifully. When I drive 70 mph, I am getting 28 mpg.

I'm considering changing to synthetic, and have some questions to determine if this is worthwhile or not.

1) Does the Nissan dealer offer the synthetic option, or do they only offer the standard conventional oil?

2) I live in a cold climate and am worried about cold starts and the wear it causes, do you feel that synthetic offers better protection for cold starts, or is all the oil in the pan regardless of type of oil and cold starts are just bad no matter what type of oil you use? I also do a lot of start/stops regardless of temperature, so perhaps synthetic would be beneficial?

3) If you go to synthetic and extend your change intervals, then the other regular "check" items are not done as per the maintenance schedule, I wonder if that could have a negative effect on your warranty?

4) Also, by going with the longer change intervals you are no longer following the maintenance schedule - does the Nissan warranty make concessions for synthetic oil and the longer change intervals, or is this a "gray area". I don't want any hassles if I need any serious warranty work later, although the chances are low.

Thanks a lot for your help!
Modified by kerrton at 1:24 PM 3/6/2009

kerrton wrote:I'm considering changing to synthetic, and have some questions to determine if this is worthwhile or not.

1) Does the Nissan dealer offer the synthetic option, or do they only offer the standard conventional oil? Some Nissan dealers offer Mobil 1 as an optional synthetic oil. Not my favorite oil as it seems to make the engine a bit more noisy at startup. I use Castrol Syntec 0W30.

Quote »2) I live in a cold climate and am worried about cold starts and the wear it causes, do you feel that synthetic offers better protection for cold starts, or is all the oil in the pan regardless of type of oil and cold starts are just bad no matter what type of oil you use? I also do a lot of start/stops regardless of temperature, so perhaps synthetic would be beneficial?

Synthetic oil can flow better in cold weather helping to lubricate the engine faster.

Quote »3) If you go to synthetic and extend your change intervals, then the other regular "check" items are not done as per the maintenance schedule, I wonder if that could have a negative effect on your warranty?

4) Also, by going with the longer change intervals you are no longer following the maintenance schedule - does the Nissan warranty make concessions for synthetic oil and the longer change intervals, or is this a "gray area". I don't want any hassles if I need any serious warranty work later, although the chances are low.[/quote]In theory if you follow Schedule 2 Maintenance you should be fine. Oil changes under Schedule 2 are every 7500mi or 12,000km. IMHO this is as far as you should go with off-the-shelf synthetic oil. Personally I do every 10,000km. I did this on my Altima and when I had a warranty claim on the motor, I simply produced my oil change records showing 10,000km oil changes intervals along with receipts. Nissan accepted this with no issues.

From what I read on different forums, it seems Nissan engines don't like a lot Mobil1 oil,... and vice versa.

Philip uses the 'heavy' 30w road, I chose the 'light' one (not that much difference between the two): I use 5w30 Pennzoil Platinum oil (Group 3 oil) which is close to a 'heavy' 20w oil.

Since the factory oil is a 20w oil, I feel comfortable in my choice and cannot wait the warranty is over to use 20w oil in the engine. Someone with an Sentra Spec V (same engine the the Rogue) use 0w20 oil and even 0w10 oil with great results (wear and fuel economy).

As you can see in the above posts, I do the schedule 2 maintenance, every 12.000kms or 6 months (which is about the same for me), and I am happy with the results so far (next oil change end of April I think).

I keep the receipts of all oils and filters I buy, and after 11 months of ownership I never returned yet to the dealer where I bought the car.

Conventional oils are really good now (I am talking about the SM rated oil), and if you don't use your car too much, synthetic oil could be a waste, especially with the Nissan's intervals.It is your choice to use synthetic oil or not, like I always say: It is your money, you earned it, do whatever you want with it, but when you have done your choice, never look back.

As promised, for those interested, here is the UOA of my third oil change.Car was at 29.138 kms, oil was used for 11.807 kms (Pennzoil Platinum 5w30).It was in use for 6 months minus one week, during the winter period.

As you can see, wear is minimum (11 in iron, 1 in copper) with only 10 in silicone.

I am easy on the engine as I never go above 2.000 rpms and if I am really careful with the car while it warmed up (about 1.500 rpm), I get 0.5 LHK gain in fuel economy. Now I am at about 7.3-7.4 LHK on my fuel tanks.

Beagle_Hauler wrote: Synthetic has been in fairly widespread use for oh, around five or six years now.

While it may be seeing more widespread use in the last 5 years or so its actually been around for a LONG time. 35 Years to be exact! Mobile 1 was introduced of Exxon Mobil was introduced back in 1974. Its claim to fame was 25,000 miles between oil changes.

Lets just say I really put it to the test.

I purchased a brand new 1978 Honda Accord off the showroom floor. At 6,200 I switched to Mobile 1 synthetic oil. Then... life got in the way. 25,000 miles came and went. I had every intention of changing it but money was tight, I was in a new job, too many bills to pay, house payments etc... and back then Mobile 1 was running $6 a quart. Based on inflation... in todays dollars that would be equivalent to $11.23 cents per quart. (Made for an expensive oil change)

Long story short... I never got around to changing the oil I starting bragging to my friends I was going to put Mobil 1 to the test and see how long it would last. Anyway... in 1984 another driver made a left hand turn in front of me and totaled my poor Accord. It had 88,875 miles on it when it was towed to the junk yard. NET: I drove 82,675 miles on the same oil... no oil changes... no filter changes.

I don't recommend it and I'd never do anything so stupid today (cars are too expensive) but ever since my own non-professional test... I've been sold on synthetic oil.

Its been in all my cars since then and you can bet when the time is right... its going into my Rogue!

[QUOTE=Cotharyus]I've been running Mobile 1 synthetic in all of my cars for almost 10 years now. Lots of good answers in here too - generally the leaks that people develop on older cars is because the seals have already deteriorated some, but are "plugged" with buildup and sludge, a few rounds of synthetic cleans that up, and the leaks manifest themselves. /QUOTE]

At what point would you not put synthetic oil in your cars. I have a 2008 Rogue that I will start using synthetic oil in our next change but also have a 2005 Toyota Solara convertible with 120,000 kms or 75,000 miles. I don't want to put any big time money in the Solara because we're retiring in 3 to 4 years

Thanks

sckeith wrote:At what point would you not put synthetic oil in your cars. I have a 2008 Rogue that I will start using synthetic oil in our next change but also have a 2005 Toyota Solara convertible with 120,000 kms or 75,000 miles. I don't want to put any big time money in the Solara because we're retiring in 3 to 4 years

Thanks

Hmmm. that's a loaded question. If you as 10 different people you might get 10 different answers. (Some answers based on personal opinion, some based on education, some on experience, some just plain guessing )

As Cotharyus pointed putting synthetic oil in an older car can lead to leaks.

This can occur because conventional oils have solvents that stick to gaskets and seals and often cause them to swell. Over time the gaskets and seals, having acclimated to the same oil for years, then switching to another type "could" cause problems. The oil you upgrade to will also have solvents and additives, however different from the original. Changing oils could result in oil leaks and/or a current small oil leak could become bigger due to the reaction the seals and gaskets might have with the new formulation. For this reason mechanics addressing questions on older cars using conventional oil will recommend that you not try synthetic oil.

However... newer engines have much tighter tolerances, resulting in less wear and longer lifespan (which is why its not unusual for newer cars to go 150,00 -200,000 with no problem). A 2005 Toyota would fall into this newer engine category. In fact 75,000 miles on your Toyota engine is a walk in the park. Practically new by today's standards. If it were me... and I owned your car, I'd make the switch.

Footnote: My 1990 Ford F150 had 140,00 miles on it with conventional oil when I made the switch to synthetic. While I wouldn't consider my Ford engine to be one of the newer, tighter breeds of engines I had no leaks so I decided to give it a shot. I figured worse case I'd develop a leak and have to change a seal. Anyway... it now has 164,000 miles on it and not a single leak or problem.