What's the best time to switch from conventional motor oil to synthetic?

[MagicMan2000]

Does anyone have any sound recommendations on when is the best time to make the switch from conventional motor oil to synthetic?

I've heard after the engine has had a chance to break in ...

I've also been told that once you make the switch to synthetic, you CANNOT go back to using conventional.

[JCL622]

Does anyone have any sound recommendations on when is the best time to make the switch from conventional motor oil to synthetic?

I've heard after the engine has had a chance to break in ...

I've also been told that once you make the switch to synthetic, you CANNOT go back to using conventional.

do it whenever u want. on that note, this "break" in period isn't really a break in period. ur motor has already undergone an immense stress test before it got loaded up and off to a dealer before it landed in ur hands.to be fair the break in period is more of YOU getting used to ur car, and in most modern cars the grade logic or some other program that adapts to your driving habits.

there is no such thing as it being bad going back and forth, tho I dont know why u would use reg when synthetic is known to be that good. my dealership uses mobil 1 full synthetic

personally i'm a big fan of royal purple and will be swapping to that when i hit the 3500 mile mark and if it's not too cold outside when i do.

the ONLY thing to watch out for is the weight of ur oil. i havent looked at the EX yet, but in the TL, the suggested use was 5w20. - turns out it's really all just a gimmick, and that a long time ago, some agency started saying that the "less" weight the less strain, and introduced 5w20 in favor instead of the 10w20.

The only time this claim is possibly reliable, is in VERY cold weather. in which case, i believe mobil1 is now also selling a 0 weight oil - again a marketing scheme....

tho if it can make the driver feel safer at heart, i guess any amount of $ is fine.

so its totally up to you. I'll go look at the engine oil cap later to see what weight we use, but there's nothing wrong with switching to it before the "break-in" period...although...u WILL use up more gas in the beginning as the car warms up to your driving habits. i've now driven it 400 miles and my MPG increased from 13 to 17 to about 19.5 now at 480 miles on the ODO.

also

u will "feell" and by this i mean i have no real means of proving it other than mine and other people's experience, tho the logic seems to make sense too, but in high weight oils, u gain a few extra ponies, so long as you dont stray very far from the specified weight for your car.In theory i guess it kinda makes sense, I have to be absolutely honest and say I did feel a difference with 10w30 and my quartermile time did improve, though i can't say it was specifically due to the RP synthetic (although i did not do any other mod on the TL inbetween the shift from 10w20 to 30)

[Poyzinous]

dont use conventional oil in the new motors. Use a quality synthetic. My Father just got an EX and its first oil change 2 days ago was 5qts of ester. Great stuff if you don't mind the price.

[Own Goal]

On other cars have liked Castor Oil Syntech. First try was back in early 90's on my Ford Explorer at about 50k. Honest to goodness picked up 1.5-2 mpg on highway. Only drawback to synthetics is of course cost and on older engines can get by gaskets regular oil won't so oil weeps ( same as leaks really). New EX only has 280 miles so I'll have this talk with my service rep in couple of months.Pure synthetics wil go MUCH longer than the dealer 3500 miles but in warranty I'll do it Infinity's way.

[JCL622]

On other cars have liked Castor Oil Syntech. First try was back in early 90's on my Ford Explorer at about 50k. Honest to goodness picked up 1.5-2 mpg on highway. Only drawback to synthetics is of course cost and on older engines can get by gaskets regular oil won't so oil weeps ( same as leaks really). New EX only has 280 miles so I'll have this talk with my service rep in couple of months.Pure synthetics wil go MUCH longer than the dealer 3500 miles but in warranty I'll do it Infinity's way.

regardless of going past the 3500, ive always kept it below 5k and done it after 3500, and yea i forgot to mention that u do get better mileage, tho when i switched weights for the summer, driving like a bat out of hell didnt help lol

Castro Oil Syntech i dont think is full synthetic....can't remember...

but for those of you trying to or learning to change your own oil or just learning about it...

make sure the brand and type you buy is FULL SYNTHETIC oil. I still love Royal Purple

[AWGD8]

Does anyone have any sound recommendations on when is the best time to make the switch from conventional motor oil to synthetic?

I've heard after the engine has had a chance to break in ...

I've also been told that once you make the switch to synthetic, you CANNOT go back to using conventional.

About 7,500 miles or your second oil change. New engine even if it was broken in in the factory (maybe few miles only) needs to have those rings and cylinder to seal. The Piston rings need to seat to the piston head sleeves and the also, needs to create a tight seal against the cylinder wall. The rings will mold the cylinder wall to create a tight seal. It is recommended to vary your RPM for the 1st 500 miles so that the piston rings will create edges evenly from low RPM to High Rpm on the cylinder wall.

This better explains it here:http://www.ntnoa.org/enginebreakin.htm

As for the synthetic oil, it is recommended to use it for the 2nd oil change. The original oil from the factory has some special additives designed for break in and helps seal the rings and cylinder. Remember, synthetic oil is very slippery and you would not use it for engines that are not tight sealed! rings, seals , cylinders... This oil is very slippery and can cause blow by to an unsealed, not well seated rings ...

And yes, you can`t go back to regular oil once used a full synthetic oil... I heard that going back to normal oil will cause some rubber seal reaction between the 2 different oil and eats up the engine seals....?????

Happy Reeving!

[Own Goal]

Good advice. Rings must seat and some say syn oil is so slipery won't happen. For example; About finished with engine going in my '86 951 Porsche. Had the cyls bored out (nikaseal / chrome) about gone so went steel sleeves. First oil will be regular Castor Oil for about an hour with no driving, oil and filter then first 250, do it again then at 1,000. This might sound excessive but it's turbo engine with lots of oil doing a lot of things a lot of places. (Build trash etc.) Will go to Brad Penn or Castor Oil SynTech at 3-4k. Of course, factory new engines do not require this sort of thing but just saying.

[Poyzinous]

Pure synthetics wil go MUCH longer than the dealer 3500 miles but in warranty I'll do it Infinity's way.

Its 3750 miles for the recommendation, but you can do 4,000 or 4,500 if you want to. Depends on how you drive. oh, and this:

[Own Goal]

OOPS! Never had one of these before and bought it for the wife. Guess I (Y?) should pay more attention. Infiniti has never been on my radar. Was all set to get an X3 but was on the bimmerfest site doing some research on son's car (99 328i) when stumbled upon their major auto trans problems with 6 speed at. One of the X3 guys suggested try the EX35. Loved the Q5 Audi but a bit too pricey. However, the local Infiniti dealer is next door to Audi dealer and had some EX35s out front. Loved the looks like never could the FX and when drove it was love at first drive.

[Poyzinous]

I'm not a huge fan of the EX necessarily, I'm an absolute fan of Infiniti however. But I will admit that it is very engaging to drive, and very comfy. Its the main reason my dad bought his. Its a nice vehicle. Especially with the Stillen Intake I threw on it

[jmess]

As mentioned above the rings are seated at the engine factory via a computer controlled break-in process. The rings are designed for this type of break-in. If you think about how fast the pistons are moving inside the cylinders it all happens pretty fast. So you can switch to syn oil at your first oil change if you want to.

[ramprun]

so what is the break-in process that allow the car to get better MPG after couple thousand miles?

[zozoka1212]

New cars comes with the rings seated in which I think is the most important. However all the movingh parts have to brake in. Even brakes,clutches etc etc. Most G owners going with syntetic at the first oil change. Make sure the syntatic is actually full syntetic not just advertised syntetic oil. As Poyzi mentioned Ester oil is good too(really good actually)Especially in our engines.

[Jason Tucker]

...Pure synthetics wil go MUCH longer than the dealer 3500 miles but in warranty I'll do it Infinity's way.

Everything in the manual says 7500 between oil changes & 1200 miles is the break in period...vary speed. Dealer said 7500 on oil change when shopping and I responded "Oh synthetic oil"...no.

[sg77]

Everything in the manual says 7500 between oil changes & 1200 miles is the break in period...vary speed. Dealer said 7500 on oil change when shopping and I responded "Oh synthetic oil"...no.

The manual says 7500 miles for "schedule 2", but 3750 miles for "schedule 1" (if you do repeated short trips, stop-and-go traffic in hot weather, etc).

[Poyzinous]

what are you doing over here zozo!? come for a fancy ?Share!Anyway, Schedule 1 or 2, Most of you guys here live in areas where I assume driving isn't disney-like or gentle. Seriously, oil change can be done anywhere between 3750 and 5000 miles, safely. Your vehicle is more than a heap of metal and glass. It (should be) something you care for, since its an investment.

[txgcoupe]

It (should be) something you care for, since its an investment.

Only if you expect it to increase in value.

Try depreciating asset instead.

John