Synthetic oil

[crashtech]

3K interval is a holdover from the days when engines seriously polluted their own internals with lead scavengers, and the oils and additive packages weren't nearly as good. Synthetic oils can go at least 7.5K in an engine that doesn't have worn out rings.

 

[z1ggy]

I change my oil at the given intervals that my manual says, which is 5,000 miles. MY last car, manual said 7,500 miles. Genesis Coupe and Impreza respectively.

 

[imagoon]

Wow, no. Just...no.

Agreed. I would have a hard believing the same oil is in there anyway. Between burn and changing the filters at 1/2 to a quart each time I would doubt the original oil is present at 200k. Not even talking about shearing and metal pollution...

 

[desy]

I go 12 to 18k on synth oil, I change once a yr top up as needed.
Normal vehicles, no turbo's, and lotsa hw driving.

 

[silicon]

I've been getting my oil changed at the Mazda dealership (because they owed me 2 free ones due to a jackass salesman) and they are using synthetic oil and claiming I don't have to get it changed until 7000 miles. I've always done the 3000 mile oil change and waiting so long past there makes me kind of leery. Is this correct, am I safe waiting until 7000 miles? I don't want to mess my engine up.

a way to know what the oil is like at an extended interval is to have your used oil tested. a lot of truck companies do this to keep tabs on the motor in case a problem begins to develop wit the bearings or other parts. i would not do as one poster does by only changing the filter...the oil does wear out or rather the additives get used up.

 

[kitatech]

We've been paying virtually the same for OCs for 40 years....for oil that so much better than it ever was...
... and people still want to squeeze another few more miles from it...

Change it with syn at 7k and be thankful that for no more than $100 a year (.00666666¢/mi) your engine will last longer than any other component in the car.

 

[Midwayman]

My MB has a 10k mile oil change officially. Requires mobil 1 and a special synthetic fleece filter and a very large capacity oil pan. I wouldn't stress out over 7k on synthetic at all though.

 

[BurnItDwn]

My (non-turbo) forester has a 7500 mile schedule with synthetic oil.

If your Mazda has a turbo, or if it's a wenkel, you may have a more demanding schedule, but otherwise, if it's an NA 4cyl, I would think 7500 is pretty much the new 3000.

 

[996GT2]

My (non-turbo) forester has a 7500 mile schedule with synthetic oil.

If your Mazda has a turbo, or if it's a wenkel, you may have a more demanding schedule, but otherwise, if it's an NA 4cyl, I would think 7500 is pretty much the new 3000.

If it's a Wankel, you're probably gonna need to add 3-5 quarts in between changes anyway :biggrin:

 

[BUTCH1]

Read some oil analysis stuff. The cheap, recycled bulk crap that you get in a $20-30 oil change is indeed breaking down by like 2000 miles.

edit:



No. Just no. Using color to evaluate the condition of your oil is dumb as shit.

I always check my mower's oil before using, I cut 2 yards with it, after all last summer the oil looked just fine, I changed it out to start the season, I just can't believe that after 50+ hours running in a high-load, hot air cooled engine that the oil was A-OK, nope, changed it.

 

[996GT2]

Read some oil analysis stuff. The cheap, recycled bulk crap that you get in a $20-30 oil change is indeed breaking down by like 2000 miles.

Maybe at Jiffy Lube, but I don't think most dealers do that.

All of the Honda dealerships over here use Honda's synthetic blend (ConocoPhilips) in their $29.99 oil changes. Ford dealerships use Motorcraft synthetic blend (also ConocoPhilips). Both are very good oils.

That said, my mechanic lets me bring my own oil + filter, so I bring what I want to use and pay him to do the oil change and also do a basic inspection, tire rotation, and top off other fluids.

The cost ends up being just a few bucks more compared to what the dealership would charge, but at the end of the day, I think it's well worth it to have an ASE master technician do the work compared to a lube tech getting paid $8 an hour at the dealership. I saw him do the oil change one time and he actually spent a solid 10 minutes checking the dipstick 5-6 times as he filled it up to make sure it was spot-on. I'm pretty sure most dealerships just dump in 5 quarts and call it a day.

 

[rommelrommel]

lol wut?

If you're serious, I'd honestly be interested in seeing what the inside of that engine looks like.

People who change every 3-5k with synthetics are just wasting money, but 200K is really, really, really stretching it. The oil you had to add during the 200K miles probably worked out to the equivalent of a few oil changes anyway.

Not to mention on most cars oil filter change ends up dropping a good portion of the oil... I guess you just dump it back in? lol

 

[jjsbasmt]

Been using synthetic oil since 1978. 5K change intervals and never a problem with my last 4 cars over those years. as a side note: Each of those cars has gotten over the EPA mpg stated on the sticker through out their life span.

 

[BUTCH1]

I run mobil 1 synthetic and filter and go until the life monitor system tells me to change the oil, which is anywhere between 10k-14k miles. My Trailblazer has 200k miles on it now, uses maybe 1/2 quart every 10k or so, and runs like a top.

It does have a 7 quart capacity so I'm sure that helps a bit with the longer intervals.

Yea, my '05 GM also has the OLM system, I change it when it says 20% life left, that usually around 5-6K miles but I use one quart synthetic and 3 quarts synth-blend and Purolator filters..

 

[Hartle4]

Yea, my '05 GM also has the OLM system, I change it when it says 20% life left, that usually around 5-6K miles but I use one quart synthetic and 3 quarts synth-blend and Purolator filters..

/the GM oil life monitors have been found to not be even close to correct. They are damaging engines and sludging them up. also syn-blend oils dont help might as well use conventional

 

[Jimzz]

/the GM oil life monitors have been found to not be even close to correct. They are damaging engines and sludging them up. also syn-blend oils dont help might as well use conventional

You have something to back that up?

 

[BUTCH1]

/the GM oil life monitors have been found to not be even close to correct. They are damaging engines and sludging them up. also syn-blend oils dont help might as well use conventional

Hmm, I've spent some time on some GM forums, Malibu forums, ect. I haven't come across any information or suggestion's or links that what you are claiming has any merit whatsoever. GM put considerable effort into the OLM system, if they wanted to shave some $$'s from their customers they could have easily just put "change the engine oil@3.5K miles" in the owners manual and the dealers would have loved them for it.

 

[Meghan54]

/the GM oil life monitors have been found to not be even close to correct. They are damaging engines and sludging them up. also syn-blend oils dont help might as well use conventional

BS. What I've seen are quite a few oil analyses done by more than a few people with GM OLM's and the GM OLM tends to be conservative in its assessments, if anything.

And I really doubt there are sludge-o-matic GM engines out there, certainly nothing like the Chrysler 2.8 V-6.

Would love to see any data proving otherwise.

 

[BUTCH1]

BS. What I've seen are quite a few oil analyses done by more than a few people with GM OLM's and the GM OLM tends to be conservative in its assessments, if anything.

And I really doubt there are sludge-o-matic GM engines out there, certainly nothing like the Chrysler 2.8 V-6.

Would love to see any data proving otherwise.

It really does take into effect the type of driving, in another forum a guy said his wife had a "soccer mom car", it never went on any long trips, ever. The GM OLM went off @2.2K miles, well below even the old "every 3000 miles" standard, since this was such a small amount of mileage he took a sample and sent it off for a UOA and sure enough, it was shot and did in fact need changing. The only "downside" to the OLM is there is no way of telling it (AFAIK) that your running synthetic vs Dino but I'd bet this will be addressed at some point with the ever-growing popularity of synthetic's these days..