Synthetic or regular oil?

[Jay]

Even today's basic dino oil is very good.

I've used mostly supertech full synthetic from wal-mart in my Z71 since new (mostly b/c it's cheap) and it's got 200k miles with no problems at all. 6k mile oil changes on the dot. same with my 07 yukon, but it's only got 48k miles so far. It has the cylinder deactivation feature and i've never had any problems or noise issues running synthetic.

On the other hand, my dad's 01 F-150 5.4L has 260k miles and all he's ever used in it is regular old Havoline on 4k mile oil changes. It uses about a quart between oil changes but it doesn't smoke or anything. He bought it new off the lot back in the fall of 2000. I tried to get him to use synthetic but he didn't go for it and it's worked out great so far. Even if he used synthetic who's to say it would not use a little bit of oil or run any better? With that kind of mileage trouble-free I don't see an issue. Other than replacing the water pump and alternator in the last 50k miles it's been a great truck for him.

The oil issue is overblown, IMO. Use what you feel is right for your truck and wallet. It really won't make a difference in the end. The only way I could see synthetics being reasonably better is in very rough situations like constant racing or heavy towing 100% of the time.

 

[BOSS]

Well....there has been some real debate over oil here, love the information guys thanks

I started reading up on additives for your drivetrain ...that's a whole different debate also. Being in and out of working on cars and motorcycles since I was 15, it's very hard to believe I didn't know certain things. Kinda made me feel dumb...went into Walmart after I did some research to read all the labels...walked out with my head hangn a little low LOL!

B

 

[Jay]

That's one thing people miss about engine oils. The crude oil itself is just a basic stock and doesn't do much in itself other than act as a fluid medium with a tolerance for heat and contaminants. What actually protects and cleans your engine are the additive packages that are included at the factory when the oil is made. The off-the-shelf bottled additives (lucas, prolube, etc) are just watered down versions of those additives without a large amount of base stock. Honestly, they're a waste of money since that level of additives won't help because the base stock will break down long before the additives become worn out.

I read a paper (SAE?) a long time ago that talked about engine oils. It was around the time EPA started it's modern assault on engine emissions starting the 90s. As regulations emerged requiring reduced emissions, not only did the fuels and emissions equipment on the vehicles themselves change, so did the basic engine designs and the lubricants used in them. If i can find the paper number I'll post it up. There's probably been several updated or all new versions of that topic on the SAE website now though.

This is when you saw Ford, GM, Chrysler, etc etc release all new engine designs during that era. The new engines not only were designed for more power and fuel efficiency, but took advantage of newer manufacturing techniques that allowed much tighter tolerances especially in the area of the piston ring pack for better sealing against oil consumption and blow-by into the crankcase (reduced "secondary" or evaporative emissions). Returnless fuel systems also came about for this reason.

As a result, ALL oils for on-road use had to be upgraded using additives that not only provided better protection but also fewer emissions across the board. It was a team effort between the automotive and oil industries.

The one additive that made a huge difference is Moly. It's supposed to be the "slipperiest" substance on the planet because it's like liquid micro-sized ball bearings. High-dollar race oils have a lot of this stuff and is a main reason for them being so much more expensive than regular oils. But even the basic cheap oils on the shelf had to be upgraded and so they got increased levels of that in addition to other modern synthetic compounds.

While great for F1 or NASCAR engines, in regular everyday vehicles that spend 80% or more of their time under 1/2 throttle it's kind of a waste to use such a highly developed oil. The manufacturers design these engines to last to their ~300k mile target engine life using the lowest common denominator: cheap off-the-shelf oils (that's not saying engine life to total failure, but just to the point where wear and tear brings down the power, efficiency, and emissions performance below certain thresholds). I've personally seen a 1994 chevy suburban with the old 350 small block go 350k miles on regular oil and while it still ran ok, it was way down on power and only got 10mpg. It also only smoked during initial start up which was probably the valve seals more than worn out piston rings. Newer engines and oils are supposed to eclipse this by a substantial amount.

That's why I say just buy what you "feel" is right for your engine and wallet. Oil changes are about the cheapest ownership cost of a vehicle. Whether you want to spend $50 a year on oil changes using regular oil or $200 a year on oil changes with a high-grade synthetic is irrelevant in costs since (excluding the purchase price) taxes, insurance, typical non-oil related maintenance costs, etc etc are far more expensive over the typical 300k mile design life. You rarely see anyone driving vehicles with more than 150k miles these days anyway.

Just one man's perspective.

 

[Poncherello]

I'm in the camp that believes the 3,000 mile oil change is a myth. I also use what the car originally came with. I have had three Tahoes in the last 7 years and always went by the oil life monitor. When the monitor reaches 0% I change it. My 2010 has 1700 miles on it and I'll probably change around 2500 miles or so only because it's a new motor. After that it'll go 7-8K miles before changes.

I have driven well over a million miles in many different cars over the years and have never experienced an oil related engine failure or any engine failure for that matter. I routinely drive 7K mile before changes in my commuter, a Lincoln MKZ. My Lexus is currently at about 10,000 miles since a change but the lease is up in 2 weeks so I'm not going to change it now.

I changed the oil in my Corvette once a year, in the spring. But that car only went about 3,000 miles a summer and then was stored all winter. I say don't waster your money on frequent oil changes or upgrading to oil not originally in the car when new.... again, I've never had an oil related failure.

 

[SmallXL]

What is the oil life monitor based on? # of miles and # of starts?

My wife's MB specifically runs on Mobil 1 and I've been told the "countdown of oil life" is the same running syn or dino based oil. The GM countdown is most likely the same.

It's probably takes little into account what is really going on while driving: Suzy soccer-mom driving the kids to schools in 70 degree SoCal weather or pulling 8k load while 120+ degree Arizona with moderate to high engine temps.

With extended mileage between changes for the syn users - better have a good filter because that will give out before the oil ever does (K&N, wics, etc.)


my $0.02

 

[Jay]

A major practice that kills oils in regular passenger cars is short drives. While your engine coolant temp can get up to 200 degrees fairly quickly, within the first few miles, the oil temps lag behind that much longer.

If the oil is never allowed to get up to 212 degrees, it can't boil out moisture (condensation) and moisture exacerbates any contaminant problems like coagulating elements from combustion gases seeping past the cylinder during the power stroke (you can't completely eliminate this... your oil would never change color if you could!). The optimum temp for oil is 220 degrees, the point where moisture boils out and the oil is hot enough to keep the additives in suspension and moving freely. Above about 250 degrees, however, you can start to damage the base stock. By the time you get to 300 degrees it's doing to your oil what happens to vegetable oil in restaurant fryers, which is breaking it down very fast and it must be replaced much more often.

The bottom line is, the additives can't work if the fluid they float in can't support them. This is how sludge can appear if you don't change the oil often enough or if it gets overheated too much or too often. If you centrifuge used oil from a well-running and maintained engine you will see a collection of sludge in the bottom of the tube. That's the stuff that becomes sludge in an engine if the oil can't keep it consolidated in suspension... again, either from too long of change intervals or if the oil is damaged.

GM has a good article on the internet about the oil life monitor. It just uses calculated values for the different factors affecting oil... like rpm, reference to coolant temp, time of operation, how much demand (throttle) is being put on the engine, etc etc. It's based on a lot of tests GM did in-house in multiple scenarios while taking oil samples at times and comparing it to an analysis of the same oil when new. Do a google search on GM oil life monitor you'll find a few articles.

 

[UofMZ71]

i just drive my truck into the gulf and get my oil there. Probably isnt as good as synthetic but itll do AND im helping the fishies...







no but regular oil ever 5k (probably about 5 months) is good for me..

 

[stayedge]

Mobil 1 or Royal Purple

i found that driving on penzoil was a better drive than on royal but royal purple lasted me a whole lot longer
and where do you go to get your oil changed for 50 dollars?
i alone paid like 100 for royal and a k&n filter
thinking of going with mobil 1 i need an oil change tomorrow
lol need a little help here =]

 

[Danny_Z56]

Todays dino and synthetic motor oils are much better and last longer than motor oils from years ago.Go with a good name brand oil and filter and you are good to go.

 

[BOSS]

After reading this thread and others, I made the switch to full synth to give it a try, went with Royal Purple in my hoe and mobile one extended full synth in the Honda.

On the tahoe - I added some non-Teflon-based Zmax oil additive. Seems they were one of the only additive companies allowed to keep the majority of their claims through the big lawsuit that swept the aftermarket additive companies years ago.

Even though I've run a can of SeaFoam in the oil every 3 changes in both vehicles, I did a quick 7min GUNK engine cleaner with a few quarts of cheap dino on both changes. Drained it, and added the full synth.

Both drive much smoother

B

 

[Z15]

Use oil additives at your own risk as you have no idea what is in them. There is no reason to use any additives with modern oils, actually the additives may lead to possible engine failure.

Aftermarket engine oil supplements are “treatments” advertised to enhance an oil’s properties. Manufacturers claim these treatments reduce friction, noise and wear; maintain higher lubricity and break down sludge and varnish, protecting the engine components. Many products advertise materials like Teflon, molybdenum or graphite; however, most fail to mention that they contain chlorine, which can be highly corrosive when mixed with water. Chlorinated paraffins were once used as extreme pressure (EP) additives in lubricants, but the practice has been discontinued in most passenger vehicle lubricants due to the corrosive side effects. These chlorinated compounds are used due to their low cost and ability to provide EP properties, but they readily react with water and combustion by-products to form acidic materials that promote corrosion of engine components and bearings.

 

[timjohnson22]

Synthetic is the way to go

 

[BWdiver]

Mobile 1 in my 05 Z71 since new with no problems and I still change it at 4,000 miles, good oil is cheap insurance.

I use no additional snake oil additives. royal purpal in rest of drivetrain.

 

[Coolade07]

ive used full synth ever since i hit 9000k on my 07. changed it between 3-4k miles religiously. i dont like driving the truck down til the oil monitor reads 0 because the oil is jus too dirty by that time.

i say go full synth.

if you have friends in the auto biz...use them wisely.

ive been spending $15 on full synth oil and labor each oil change w/ free tire rotation.

 

[FijiRob]

I run Royal Purple and am very pleased. In fact, i went 10k on my last oil change interval and decided to send the oil to a lab to see how well it held up and how well my engine was wearing.

The lab result came back perfect! The oil had maintained its viscosity and none of the levels were out of line. My engine is in top notch condition. The lab recommended continued oil change intervals at 10k.

 

[OklabyGodhoma]

Before I retired I spent many years as a Quality Assurance Manager for a military "Motor Pool". Oil use and consumption were always a great concern of vehicles put to the hardest usage. During routine maintenance we tested the oil utilizing an instrument that measured the amount of carbon and impurities in the oil. This is the optimal way of determining if oil indeed does need to be changed. Most people are not going to put out $2200.00 for such an instrument. Other ways of determining when oil should be changed is by actual hours of run time via the use of a "Hobbs Meter", or by mileage.

I have run Mobil 1 since it was first made available for public use; yes the military had it first for a great number of years. I have had a Volov 244 with 286,000 miles with NO oil usage as well as an S-10 with 261,000 miles again with NO oil usage. Currently both of my vehicles (Volvo S70 and 2007 Yukon XL) use Mobil 1 only. NO I do not receive money from Mobil (wish I did) but can attest to how well it works. Unlike parafin based oil synthetics do NOT break down from wear nor do they change viscosity and the "boiling point" is almost 400 degrees greater than "normal" oils.

From my Oct 4, 2009 posting in a simular thread.

Now for what you want to know. Your type of driving plays a great part in how often you change your oil, if you are using Mobil 1 a good rule of thumb is if most of your miles are from city (stop and go) then change your oil and filter every 10,000 miles. On the other hand if your miles are mostly highway then every 15,000 miles for oil and filter. I have personally tested Mobil 1 in a lab after 15,000 miles and found that if I were to filter the oil through a 6 micron filter I could put the oil right back in the vehicle. Remember, the carbon from combustion and other impurities are suspended in the oil and this causes your wear.

Also I use only WIX filters, more filter media and constructed so the flow thru utilizes all of the filter. I urge anyone to take the time to cut filters apart after they were used with a hacksaw and you can see exactly what I mean.

I do wish there was a way to specify the type of oil in use for the DCM to be more accurate....but lets face it, everyone here can do basic math.

---------- Post added at 11:22 PM ---------- Previous post was at 11:20 PM ----------

From my post two days ago in another thread.

Yes you can change to synthetic oil even on a high milage vehicle. Key things to remember:

1) Do your first change of synthetic after 4000 miles and be prepared for lots of dirty oil to come out.
2) Pay attention for any leaks to suddenly show up. Remember lots of oils out there are parafin based (wax) that leave potential leaks plugged with wax. When synthetic is introduced it starts removing that wax buildup and leaks may appear.
3) Depending on the number of miles on your vehicle you may either want to opt for a thicker viscosity of synthetic or use a "high milage" synthetic.
4) Whatever synthetic you choose feel at ease at extending your milage between changes significantly. Please see my earlier post in this thread about personal history and lab testing.

Enjoy and don't be at all suprised if after 1 - 2 thousand miles that your vehicle seems to have more pep.

 

[acainindy]

I have been using Royal Purple since 2009 and I am very happy with it. I use the Royal purple filter too.

 

[OklabyGodhoma]

Royal Purple has a good rep....never disected one of their filters.

 

[stepjl]

Mobil #1 Syn is #1!!!!!!!

I have been running Mobil #1 SYN since I first learned about it in 1984 while working at a Mobil service station when I was a kid. There are MANY brands on syn oil now on the market, but I am a loyal Mobil #1 user. Use syn over conv oil no matter what brand. Amsoil I've read is the best $ can buy, but cost more. I run mine till it gets dirty... 4,000 to 6,000 miles. Anytime in that time frame when "I feel like it". You can run it longer as some on here have stated, but I would not go past the GM timeframe listed in your owners manual if you are under warrenty. Also, if you are going to run longer, I would still change out the filter/add a QT if going to do this every 5,000 miles or so. Mobil has a special Mobil #1 that says on the jug it is for EXTENDED use of around 15,000 miles.

 

[01HDtahoeNJN]

just hit over 100,000 milesi want to switch to synthetic but my uncle has a (1995 tahoe at 180,000 miles eith no prob on regular.) But I need this thing to last forever love it to much! What do you all think?