High Mileage Oil vs. Regular Oil

[VideoTechMan]

For those of us who still drive older cars like myself; I drive an 84 Olds Cutlass Cierra and I have always used 10-40 oil in my car whenever I do my oil changes, and it has been the same oil I have used for many years and have never had any problems.

Now I have been seeing motor oil in stores now formulated for high-mileage engines that is supposed to help your older engine from oil burnoff and other things. Does this type of so-called special formulated oil really make a difference or is it no different from your regular oil?

My car now is at 163K miles and still going strong, so I dont really see a reason to change oil formulations.

VTM

[HRMaddie]

I wouldn't change the type of oil you are using now. I have no scientific proof that higher mileage oil is better for higher mileage engines, but my opinion it is just another marketing scam. Regularly scheduled oil changes, with a good oil filter and good oil seems to be the best preventative maintenance.

[smearbrick1]

I imagine these motor oils simply include the same ingredients they use in those engine restore oil additives.

For higher mileage engines, those additives work well. They fill miniscule gaps to help boot compression and ultimately horsepower. Other additives that lessen the viscosity of the oil (slick 50 and the like) do more to harm your engine than good (some would argue). Of course, then again, some would argue full synthetic oil is not good for your engine.

[Shocker Milwaukee]

I've used nothing but Mobil 1 10-40 in my car (96 Nissan 240SX). I'm at 175K & still going strong. My mechanic is changing the timing chain for the first time as I type this. I'll ask him about the engine wear when I pick it up & post his opinions.

[SquirrelDip]

I'm going to agree with HRMaddie here - use a decent oil and regularly scheduled oil changes.

On an older enging do you want to increase compression and horsepower?

@smearbrick1 - what's your take in using a semi-synthetic oil rated at the correct viscosity? My understanding is that it doesn't do much for performance but it breaks down slower and basically just works better...

[shelbyGT]

I think those higher mileage oils also "condition" old seals in the motor.

I agree, I think the biggest difference between regular and high-mileage is that they add chemicals to help with seals, et cetera.

[zzyzzx]

If I had high mileage on my engine (I don't) I'd use Seafoam instead of higher mileage oil.

[smearbrick1]

I'm going to agree with HRMaddie here - use a decent oil and regularly scheduled oil changes.

On an older enging do you want to increase compression and horsepower?

@smearbrick1 - what's your take in using a semi-synthetic oil rated at the correct viscosity? My understanding is that it doesn't do much for performance but it breaks down slower and basically just works better...

From what I've read, there isn't much of a benefit to running synth blend (as you stated, the breakdown would be slower. Ultimately, you're still running a partial non-synthetic) If it were me, I would run a full synthetic. The cost difference between running a full synthetic and synth blend is negligible.

I realize my post sounded as though I was downing full synths, but I was merely stating that there are some who don't agree they are all they are cracked up to be. I, for one, think they are very beneficial.

I ran a gl-5 full synthetic (mobile) gear oil in my 1995 Probe Gt (for future reference, you should only run gl-4 gear oil in a Probe's manual transmission because it lacks the sulfur additive of the later gl-5 oils... sulfur + brass synchros = ruined synchros). The synthetic, by far, outperformed the non-synthetic. Of course, in a transmission (I realize we were talking engine oils, but the only reference I have is gear oil) like the probe's, which runs pretty hot, a full synthetic is the way to go.

Quick story: I bought my 95 Probe GT in about January. When I bought it, I was having serious problems with grinding gears and gear engagement (especially reverse and 1st gear). After dicking around and procrastinating, I finally decided it may be a good idea to check/change the gear oil in the transmission. So I pull the drain plug (after placing the pan underneath, and immediately oil starts to run out. Usually this is fine, but the smell from the oil was almost unbearable. Not to mention the fact that oil only ran for about 30 seconds and stopped. Apparently, the previous owner had never checked the transmission gear oil. When it was all said and done, the transmission only had about 1/2 quart total in it. After filling it with about 4 quarts of Mobil 1 Gl-5 (they didn't have gl-4. Anything was better than nothing at this point.) and a few minutes of warming up... the transmission shifted much better.

Moral: check your oils (notice the plural) regularly... engine, front/rear differential...etc.

Sorry this went on so long... I'm a bit long winded... besides, I love cars.

[ZAPPER]

The oil debate has been going on as long as the engine has been around. I don't really have room to talk (I am bad about changing the oil on time) but I have gotten over 150,000 on everything that I have owned 300,+ on a full sized pick-up with a 302, 200,+ on a 4 cyl Ford 2.3, 200,+ on a dodge 6 cyl. I say that driving habits are a very big factor. Don't redline your engine to go 20' and just as important and less known is the decelleration. Once you do attain high revs, dont just drop of of the gas, ease it back. Your engine is designed to put out power not take it in. The sudden decelleration puts all kinds of stress and whiplash into your engine. You don't have to take my word, check it out for yourself. Get under the hood and rev your engine, it will build revs at a pretty good rate depending on what you have. But notice that if you just dump off of the gas it will not slow as smoothly. Same thing with a pitchers arm, It is not so much the throw that causes injuries, it is the decelleration of the arm after the pitch that does the damage. A pitcher reaches back and uses the whole range of motion to put power into the ball and has very little time or range to slow his arm down. The same thing goes on in your engine, as it is being fed fuel it builds to speed using its design to counter fuel force and turn it into mechanical force. When you drop off the fuel supply the mechanical parts of your engine no longer are working as they where intended.


Meanwhile back on the ranch, I don't know for a fact but I have heard that the biggest function of oil is not the lubercation, but the cooling that it provides. The spaces that oil lubes are so small and of such tight tolerances that you only need a few drops to do the job. The oil baths, splashes and sprays are to conduct heat away from the metal (and yes to replenish the lube in the tight spots) So keeping it flowing inside your engine is paramount. Keep the galleys and passageways clean by using a good quality and amount of oil

[jackal70058]

I not an oil expert, but my dad is an engineer for oil company and knows a lot about it. He never uses the syntetic oil, always says the regular is just as good. He must be right, because the only I use is the regular 10W30 and the car is running today. It is over 15 years old. I have no problem with the engine at all and runs like it is brand new. If I could only say about the body. I'll need work there.