Soundeffects

iTrader: (2)

My roommate use to have this 1992 twin cam Saturn. It was changed it 1998 when it was bought and maybe once in 1999. NEVER AGAIN changed. It had roughly 200-215k on it, the car was a best.

We don't even know what kind of oil filter was put on it in 1998 or 1999 because it was covered in dirt since then! He only added oil when the oil pressure got low, I think it would have ran better if he monitored it but he didn't care if it was 2 qrts low as long as the pressure didn't drop below his mark on the dash. I swear the thing was pretty fast and we put in $.99 oil from the gas station so nothing special. He left for a couple years in the air force and the car sat under a pile of dirt on the sid eof his house only to get abused when he came home every once in a while. It finally died about 5 months ago, it was low on oil and he didn't add any in for a month or so, the oil light came on and then it was too late. It end up producing a knock but still ran so we just gave it away.

Long story short GM and cheap oil=lasted a hella long time.

daveZ insanity

iTrader: (4)

I know you're not suggesting this, but a lot of people actually do it. Our engines are not "water cooled" - they're "water and oil cooled". The oil carries a lot of heat away from internal parts like valve guides, and it gets too hot when the volume drops below a minimum amount, causing premature wear. I don't know what that minimum is, but 2 quarts is probably below it for a 5 quart sump. To some degree it depends on the shape of the sump and the oil pickup design / location.

Low level also causes aeration at the sump pickup tube inlet in hard corners - it can slosh away and uncover the opening.

Dino oil starts to break down at temps above about 250, so it loses lubricity and parts can wear a lot or break. At least synth will remain usable to well above 300 (my Formula Vee ran oil temps of 285+ at the end of most straights).

Mathys

iTrader: (3)

I do it every 10k, but apparently the fuel here is a bit better quality than in the US....

03performz

iTrader: (8)

That's crazy, I never new that Mobil 1 changed prematurely. I always assumed that the color change characteristics were the same as conventional oils. When I change it and its' dark after 3k, I always assumed that it must need it. Thanks for the heads up but I'm still going to change it at 3k. Just because your engine will "last" or run for a long time w/ longer intervals doesn't mean sht to me. I'm only concerned w/ engine wear and compression. Yeah your engine may still run for 300k but how close to the original hp are you at.

JonsilvZ

I drive under 5k miles a yr. Twice a yr oil change. Using Mobil 1 since 6k currently have 31k. My other car is a 96 Infiniti G20 with 99k miles it doesnt use a drop of oil! I use Quaker State full synthetic.

pony_killer

iTrader: (23)

I supposed I can test the lady out for 7k miles without doing an oilchange and post what the results are. I purchased my car back in January of 06 and the most recent oil change I did was the end of July at 5200 miles with Mobil 1 synthetic & the OEM oil filter. Hopefully if all goes well she'll run fine until 12,500 without an oil change. But if something bad goes wrong...you guys will owe me a new 07 Z...savvy?

daveZ insanity

iTrader: (4)

Do what makes you feel comfortable, for sure. But I'd be surprised if even one of you has had an oil-related failure. In my experience, with a new car or fresh engine rebuild, you can change dino juice every 7.5k and not lose any compression at all for 100,000 miles or more. With synthetic, you probably have no worries for twice that, barring random parts failure or an assembly fault. Even in old cars with 6-figure mileage and unknown maintenance histories (five 356 Porsches costing me from $400 to $2500 each, a 10 year old 280 ZX with 100k, a few ratty Mini Coopers, a '72 MG Midget etc etc etc), I've not had a failure I could blame on lubrication.

I used to run a leakdown test every year on my tow vehicles and after every event on my race cars. I've found no loss in any street engine changing synthetic oil + filter every 15k and the air filter every year. I've never had an oil-related DNF either. In fact, the only mechanical DNFs I've had in 25 years were from a brand new timing chain that snapped on the first lap and from the cracked valve adjusting screw that resulted from it (and that I didn't find until the next race). My third and last DNF was when I ran out of gas at Lime Rock's Vintage Fall Festival in 1988.

You can buy a leakdown tester for the cost of 2 synthetic oil changes at a dealer (about $75) or you can build one for about $20. It takes little more time to do a leakdown test than it does to change your oil and filter without a lift. You do need a source of compressed air, though. Alternatively, just buy a compression gauge at Pep Boys for $15.

Luv4daZ

every 2,000 miles!

ZPatrick

+1

Tenac1ousZ

iTrader: (2)

Based on a lot of tests I've read, I would not be surprised if Synthetic oil could protect well over 5-7k miles.

With that said, though, I still change my oil (m1 systhetic) every 2-2.5k miles simply because the engine feels a lot smoother and more responsive with new oil -- the engine feels lighter when reving. Oil gets thicker as it is used, so that could cause some drag at high-rpm. After 9 oil changes now, I've noticed that the engine starts to loose its smooth feel around 2k miles, so that's why I change at 2.5k miles.