if you are using mineral oil stick to it, changing to synthetic is not going to give much, only higher consumption. when you are getting brand new car or with few tousend miles use synth but later imo there is no sense.
A while ago I changed from mineral to synth(car had like 70-75k) and was surprised, after 5k miles I had around 1 quarter of oil left! from then I just stick to mineral valvoline 5w 30 and I'm happy.

did u just say that it makes no sense for engine protection to switch to syntec unless it is less than a few thousand miles?
Engine parts continuosly weatr out that's why they inented filters.

I bought my 5.5 at 97,000 and switched to synthetic (assuming prior owner used convetional) at the second change. Used the Amsoil engine flush immediately prior to the switch. Can't say I really noticed a change in consumption, nor oil color near end of drain interval, and I was looking for both.

At the same time, I like knowing that my engine is wearing at a slower rate with synthetic. I want to put the need for a motor swap off as long as I can. An engine swap would obviously hit the wallet much harder than a few extra bucks with every change.

Changing every 3000 also helps stave off the swap.

Synthetic oil does a much better job of reducing engine wear than mineral oil. It will last longer before requiring a changeout than mineral oil, which is a convenience for many of us. How much longer depends on many variables, but IME you can go twice as long without causing issues. I like it because I change both oil and filter every 5k and maintain excellent lubrication.

Changing from mineral oil to synthetic used to be a risky proposition in the early days of synthetic, because the oils might have compatibility problems. People said that synthetic caused more oil leaks - which, interestingly had to do products formed by the mixture of mineral and synthetic that chemically attacked the oil seals and damaged the seals. That is no longer an issue, as synthetic technology has converged and the manufacturers realized the problem with interactions and modified their products accordingly. The recommendations and tricks for avoiding the incompatibilities are no more valid than old wive's tales anymore.

The only point to note about changing oils is that it takes a change or two to fully replace the effects of the previous oil with the benefits of the newer oil. (The oil likes to soak into and bond onto metal surfaces).

Will your engine wear out prematurely if you don't use synthetic? No. There are examples of people who get 300k on mineral oil. But the UOAs and engine builder stories all fall heavily toward synthetic as better for combatting wear.

Dave

What Dave said.

I'd rather spend an extra $18 on synthetic oil (3 quarts over 6000 miles or so) to ensure adequate protection for my engine even if maybe it burns the synthetic oil at a somewhat faster rate.

I attract some attention whatever I sad above is based on information from mechanics also nissan mechanics. I guess they were full of BS.

New car engine are prep to run on any oil from the factor. If you losing a lot of oil check the ground and take a look at the rear valve gasket.

Reviving a old thread...

My car burns alot of oil and I bought the Valoline Synthetic oil 10-30 now I'm thinking it's crappy compared to Castrol and I'm debating just taking it back and getting the good stuff.

I have a 02 with 155k

Switching from Mobil1 to Valvoline High Mileage (synthetic blend) a couple oil changes ago, haven't noticed much improvement in oil comsumption (still around 1500-1800 miles per quart burned).

Same here (with Castrol High Mileage mineral)

Same here no matter what oil it is. It gets sucked into my intake through the pcv. Theres always something in the catch can.

I know my rear valve cover is leaking enough to leave a small (quarter sized) drop every other day, can smell it when I turn off the car after driving on the freeway too. Consumption was a quart every 1700-1800 miles before I noticed that so whatever is leaking isn't that much.

On the plus side, I'm not burning enough to affect the spark plugs.

Castrol 5w30 gtx + Lucas synthetic stabilizer ftw

HAHA! That was great. I've been running mobil1 synthetic for over three years now and it still burns exactly the same 1qt./1500 mi. PCV valve didn't help, and my spark plug tubes fill up too slowly to equal that amount. But thanks for the laugh.

PCV change didn't help me either.