mobil one synthetics, oil filter intervals?

Guys, let's throw some facts on the table to discuss this. 3000 mile oil changes date back to the 50's and 60's. Back then, piston/ring/cylinder wall tolerances and metallurgy expansion control was significantly more primitive and isn't even close to what we have now. Blow-by was a huge problem thus causing dirty oil. For the most part, on a stock engine, we have elimated the majority of that. Most maufacturers, especially foreign, recommend 15K miles between oil chanes for their synthetics. Mobil used to recommend 25K miles between oil changes. So, then what is the reality?

Some of the cars measure dirty oil by shining a light through it for analysis. When it's dirty, it gets changed. BWM is known for it's 15K changes and I'm thinking they are pretty knowledgeable and protective of cars costing $100K.. I'm sure some of our cars cost that much :).

In a test of Mobil 1 synthetics on taxis in New York, they took half the taxis and sealed the engines for 60K miles. The other half the just changed the filters and added oil as needed. At the end, on the taxis that were sealed, they found the engine had similiar wear to mineral based oil but they had no oil filters left. The filters had disintegrated. On the taxis they changed the filters on, they had no measureable wear at all.

Part of the key to this is the quality of the filter. I use Mobil 1 filters because the synthetic doesn't disintegrate.

In personal experience, I have 3 definitive measureable stories. My 86 cougar with the 3.8 liter 6-cylinder went 186,000 miles with no oil change less than 10K miles and most around 12K miles. I never added one drop of oil between oil changes because there was no noticeable loss of oil. Too bad my cousin rolled it down a hill.

On a 1978 750 honda that was track raced, we had to rebuild the engine about every 4 races due to compression loss. When we switch to Mobil 1 synthetics, we ran that bike for 7 more race weekends, 14 races, and had no noticeable compression loss. We finally tore the bike down at the end of the season and the bike still had hone marks in the cylinder walls and no wear marks.

My last Toyota truck went 256,000K miles before it was stolen had the same 10K+ oil change schedule. I bought the truck at 60K miles and probably added 1/2 quart between changes always. When I first put Mobil 1 in there, the oil went pitch black at 500 forcing an oil change. The crud that was in the valve covers started coming out. I had to change the oil at 1500 miles the next time because of all the crap coming out. After that, 10K mile or more and the inside of the valve covers that was black **** now became clean enough to eat off of.

On an engine with a blower, it's slightly more complicated. The added compression caused by the blower will caused blow-by, and thus more crap in the oil. So, oil changes in that environment are going to be more dependend on how often you get on it, how much pressure you are running, etc... I change mine at 5000 miles and add 1 quart if I do a road track day. I think the reason I need oil though is that a bunch of it gets sucked into the blower through the valved cover.

On a non-blown engine. I'm totally comfortable with 10K+ oil changes with a Mobil 1 filter for most people. Put some science behind your decision. If you aren't sure, get the oil analyzed. The old wives tale of 3000 miles though really needs to be put to rest. If you don't think oil has gotten better in 40 years, keep changing it at 3000 miles and making the oil companies richer. They don't have enough money yet.
 
If you use Mobile1 it's a catch 22 situation. It will indeed last but it still gets contaminants in it after miles just like any other oil. I run it in my wifes BMW and my Honda (I commute 120 miles a day) and change it every 6k. I stopped running it in my Cobra and Lightning because of how frequently I change the oil in those. I probably only drive them 3k a year each but almost all those miles are really hard miles so I might change the oil 2 or 3 times a year....especially the L because of the nitrous. For the toy's I run the Motorcraft synthetic blend which comes highly recommended by a lot of mechanics. If you are running Mobile1 and change it religously every 3k you are tossing you're money out the window unless you really beat the piss out of your car. A sythetic blend would more than meet most peoples needs. If you are so inclined to use the expensive stuff and change it alot- there's nothing wrong with that either. Keep in mind though that oil change frequency should be different depending on how you are using your vehicle.
 
helty said:
3000 miles or bust. i know some people think thats wasting money nowadays, but thats just me.
+1 3000 miles or bust is my moto.I would never keep oil in my car for that long and just change the oil filter and add oil as needed I think that's retarded.
I only do four oil changes on my mustang every year so,it doesn't matter to
me.
 
Pennywise2 said:
+1 3000 miles or bust is my moto.I would never keep oil in my car for that long and just change the oil filter and add oil as needed I think that's retarded.
I only do four oil changes on my mustang every year so,it doesn't matter to
me.
like san~man said, $30 every 3 months for peace of mind, I dont care if I am wasting my money. $30 is dinner for two at TGI Fridays. For that I can stay in and make some mean grilled cheese, just one night out of 3 months.

My first car was a 93 Cutlass Supreme with a 3.4l DOHC V6. Ran a blend in it from 80k to 124k, changed the oil at 3k intervals. One time I let it slide to 3500 miles, and it cost me the motor. Ive seen those same cars with the same motor run well over 200k, so it wasnt a case of high mileage.

I guess for me its a case of once bitten, twice shy. So be it.
 
helty said:
like san~man said, $30 every 3 months for peace of mind, I dont care if I am wasting my money. $30 is dinner for two at TGI Fridays. For that I can stay in and make some mean grilled cheese, just one night out of 3 months.

My first car was a 93 Cutlass Supreme with a 3.4l DOHC V6. Ran a blend in it from 80k to 124k, changed the oil at 3k intervals. One time I let it slide to 3500 miles, and it cost me the motor. Ive seen those same cars with the same motor run well over 200k, so it wasnt a case of high mileage.

I guess for me its a case of once bitten, twice shy. So be it.
I belive it.Nothing is worth more than peace of mind San~man is a
smart man good saying. :nice:
 
I had a 93 LX 5.0 and ran only Mobil 1 and Motorcraft FL1A filter, changed both every 5,000 miles. The car had 271,000 miles when I sold it. The guy who owns it now stopped by this weekend, has 292,000 and the motor has never been into. Doing the same for my 2003 GT. Just my $0.02.
 
I don't remember where it was that I read this but I think it's a fairly good testament to the lubricating power of synthetic oil...These figures arent set in stone by any means being as it was a long time ago that I read it but there was a test done on 2 engines, 1 ran nothing but dyno oil and the other ran nothing but synthetic. They then drained both completely and let them run oil-less. The dyno-oiled one siezed up within a couple minutes while the one that had been running synthetic lasted over 30 I think it was. Just goes to show that you can afford to cut back on the frequency of your oil changes if you're using synthetic oil.
 
To each his own, I don't bother trying to convince someone about facts when they probably don't care what you are saying. For those of you who are changing your full synthetics every 3000 miles your just pissing that cash away. You may not care, oh well but I let mine go extended and have no problems. I also use a high quality filter for extended intervals, not a crap one. To me the extra cost of the filter/synthetic oil is worth it if it keeps me from changing my oil that often. Maybe I'm just lazy.