1 Mobil 1 change vs 3 dino oil changes

[tai]

This is kind of inverse to the discussion about the economics of using Mobil 1 vs. a more expensive synthetic oil.

Since Mobil 1 is such a standard here, let's compare it to an excellent conventional oil, like Castrol GTX or Pennzoil Purebase.

For the price of one bottle of Mobil 1, usually about $4, one can purchase 3 bottles of GTX.

Conservatively, Mobil 1 should last 10K miles. Let's be more conservative and say 9K miles. For the price, I can get 3 changes of GTX, lasting 3K miles each.

OK, you also have to factor in the filter. To be fair, for the GTX changes, the filter is changed every 3 changes, meaning some old oil is left in there with new GTX oil. Does it matter much?

Considering the scenerio above, would using GTX (or some other good conventional oil), and changing it more often, be better for the engine than using Mobil 1 for an interval 3x as long? Or, to put it another way, does Mobil 1 last 3 times longer than the best conventional oils?

 

[oilboy28]

I guess only oil analysis will tell, let us know what you find.

 

[Patman]

Just based on the time you save, going with a synthetic and 9k changes is the way to go. I agree though, oil analysis is probably the best way to see which of these two plans is best for you.

 

[cak446]

I don't trust extended drain intervals, unless oil analysis is done and/or a bypass filter is installed. I would rather change conventional oil more often, instead of running synthetic three times as long. I have several reasons for my stance on this situation.


1. Contaminates build up in the oil at relatively the same rate whether or not synthetic or conventional oil is used, and an oil change is the only way to get rid of the majority of these contaminates. This is important to me since I drive a diesel and my oil change intervals are basically determined by the amount of soot in the oil.

2. Regular oil changes can reduce the damaging effects of unknown engine problems such as: excessive silicon in oil due to poor air filtration, fuel dilution do to a flooded engine, glycol in the oil from a poor head gasket. A good example of this occurred with my brother's car. During an oil change I noticed an air intake clamp was very loose and the inside of the intake was very dirty. I don't know how long that clamp loose and I would hate to see an oil analysis on that oil, but the since the car had conventional oil changes every 3000 miles the damage would be much less then a synthetic oil with longer drain intervals.

3. I enjoy doing oil changes, since it gives me the chance to craw under the vehicle and give it a good checkover. Problems such as torn CV boots, bad suspension components, and fluid leaks can be detected sooner and fixed before they cause bigger and more expensive problems.

Carl

 

[FowVay]

Don't forget the ancillary aspect of oil changes. You are consuming a non-renewable resource, you're putting 3 times the number of plastic bottles with residual oil in them into the land fill, you're putting 3 times the number of oil filters that are usually full of residual oil into the land fill, you're making 3 times the number of trips to the recycler to dispose of the old oil and you've made 3 times the number of trips to the store to buy the product in the first place (unless you buy in bulk). This represents a huge amount of waste.

If you can get the same OR better wear protection while reducing consumption and conserving any form of energy then that is the better way to go - IMHO.

free tibet, save the manatee, eat more chicken, "Have you hugged your tree today?"

 

[cryptokid]

i think no body can go wrong with the 3k change. thats an instant guarintee for long engine life. the synthetic issue is an almost guarintee too, oil analisis is costly! ecenomically, synthetic is not a win win situation once you factor in the cost of oil analisis.

and also, if a synthetic can go 9K with a single filter, why cant dyno oil go 3 3k changes, but only 1 filter every 9k? its not like synthetic can some how disolve solid particles into nothingless. oil filters dont get clogged by oil, they get clogged by solids. lets say i drop a grain of sand down my filler hole, reguardless of weither its synthetic or dyno, it is still (hopefully!) going to be trapped by the filter.

 

[Spector]

I don't believe anyone knows the answer to your questions simply because no individual or company has ever done a study out to say 100,000 miles on similar cars etc and never will due to cost and time.

As noted above, changing oil and filter every 3000 miles (assuming you like to do it) will give you 100,000-200,000 miles the same as doing your synthetic with extended drains. It really comes down to what you feel comfortable with. Without the cost of time, hassle etc. there is no question in my mind that a cheap dino every 3000 is less expensive then synthetic and I have used synthetic for 10 years. Analysis just adds to the cost and tips the scales even furhter to dino if cost is a factor

 

[cryptokid]

maybe my previous post was to harsh. i do know synthetics when done properly will be just as good as dyno, and even better. but its not ecenomical because of analisis, which isnt required with the 3k thing. i didnt mean to sound harsh against synthetics.

 

[Al]

quote:

---

Originally posted by cryptokid:
maybe my previous post was to harsh. i do know synthetics when done properly will be just as good as dyno, and even better. but its not ecenomical because of analisis, which isnt required with the 3k thing. i didnt mean to sound harsh against synthetics.

---

I don't think you will get the knock down endless arguments about the virtues of dyno vs syn here. You can do that on the Edmunds board

Well oil analysis can be important even on short drain intervals. It will spot fuel dilution, coolant system leaks, leaking intake, and incomplete combustion, as well as abnormal wear. I think it is worth doing one once a year irregardless of the drain interval. just my opinion.
I totaly agree with Spector here-there is no data that correlates wear products with engine life-unless it's extreme.
However, aside from the obvious hassle of changing oil frequently-I think synthetic gives your engine a margin of safety when bad things happen. It gives me a little more peace of mind for times my wife and daughter (even though she's 30

) are out on the road (rightly or wrongly). Also I wouldn't recommend not changing filter for 3K changes-you are leaving dirty oil in the system.
As Spector says-whater you are comfortable with.

 

[Kernel Potter]

Keep in mind, that even though it may be hard to determine, unless it is a very obvious, immediate and consistant change, that a true PAO/ester synthetic may give you 1-3% boost in mpg. What makes this all extra difficult is there may not be an actual mpg increase at all. For all we know, it's possible the Castrol GTX may give better mpg numbers. But the point is, odds are the PAO/ester oil will have a good chance of slightly boosting mpg; so....

Even a very small mpg increase would come close to paying for the synthetic oil over its usage interval. The savings would be almost transparent since it would potentially be only about 10-25cents per fill up. Nevertheless, it may still be saving you that money despite not realizing it.

Besides that, you have the excellent deposit control of Mobil 1, extreme heat protection and insurance and excellent cold pumping performance. I see that the cold pumping won't be an issue in TX however.

With the benefits of the PAO/ester and the likely mpg increase, I'd just do 7,500 mile intervals and figure you're still ahead.

In fact it's exactly what I plan to do on my new car that is now approaching the end of it's break-in.

 

[Eiron]

Al brings up a good point I've never thought of before. I've never heard of anyone who does 3k changes ever having an oil analysis done also. The assumption is always, "I'm draining all the cooties, all the time!" But the reality is, if you're not doing analysis during three 3k changes, why would you think it's necessary on a single 9k change? If you assume (based on "established logic/tradition", anecdotal evidence, marketing, whatever) that dino's offering enough protection to go 3k, why not use the same evaluation to run syn to 9k? If you don't care what's going on inside your engine for three 3k dino changes, then forget about it for one 9k syn change. You can still get under the car every 3k to inspect things, if you like.

Another excellent point is made by Kernel Potter (OK, how did you get that handle??). A premium syn will protect & clean in ways other oils simply can't. When you add in "transparent" benefits, it's even better.

I'm not planning on doing oil analysis forever. I'm planning on establishing some baselines, so that I have a better idea of what's really going on. That way I can graduate from a dino-based WAG to a syn-based SWAG!

 

[TheLoneRanger]

I am one of those people who have used synthetic oil in the past, and have gone back to mineral. I didn't see a benefit to using syn. The extended drains aren't a positive, because they allow more of the soluble contaminants to build up. Pumpability isn't an issue, if you pick the correct weights for your climate. (An extremely cold climate is an exception) I've also noticed that the mineral oils keep the engine internals just as clean as did the syn.

Tinkering with my vehicles is a hobby, so I don't mind changing oil. I can also spot potential trouble much faster than an oil analysis can; by checking coolant levels, loose clamps, air intake, etc. And the Fumoto drain valves make a change quicker and easier, and it's almost fun....

So for me, my choice is the GTX with 3-4K changes.

[ February 12, 2003, 10:41 AM: Message edited by: TheLoneRanger ]

 

[tai]

A bunch of good points and questions were raised.

About the ancillary effects of oil changes, if the oil is recycled, and the filter left in, then I don't see much environmental impact. Even considering the cost of recycling, maybe synthetic oil processing products more waste byproducts than processing conventional oil. I don't know.

But Kernel Potter's point about the effect of synthetic on fuel economy is excellent, and something I forgot about. In 3000 miles, my car, which gets about 25 mpg, will use 120 gallons of premium. I just need to use 8 gallons less with synthetic to offset the price difference: 8x$1.50(gal of gas) vs 4x$3(syn qt of oil premium over conventional). That's an improvement in fuel economy of 6.7%.

Can a good synthetic provide that economy improvement over a good conventional oil? I don't know, but I'm sure there is some improvement, which means the initial cost of purchasing synthetic oil is offset somewhat. If I keep my synthetic oil in the car for a little longer than 3K miles, say 4K or 5K, the synthetic premium in cost is probably totally negated by then.

I'm probably not explaining the math too well, but I'm now much less certain about the economy of using conventional oil for a given change interval vs. synthetic.

 

[Ken2]

quote:

---

Originally posted by cak446:
I don't trust extended drain intervals, unless oil analysis is done and/or a bypass filter is installed. I would rather change conventional oil more often, instead of running synthetic three times as long. I have several reasons for my stance on this situation.


1. Contaminates build up in the oil at relatively the same rate whether or not synthetic or conventional oil is used, and an oil change is the only way to get rid of the majority of these contaminates. This is important to me since I drive a diesel and my oil change intervals are basically determined by the amount of soot in the oil.

2. Regular oil changes can reduce the damaging effects of unknown engine problems....

3. I enjoy doing oil changes, since it gives me the chance to craw under the vehicle and give it a good checkover.....

Carl

---

1--Not exactly. Much of the contaminants in the oil is caused by the breakdown of constituents in the oil. Better oils reduce this, thus the reason for longer oil drain intervals.

2 & 3 --True.

Diesel? Look at this analysis of a standard petro oil, Mobil Delvac 1300 Super 15w40 with 25,000 miles in a big truck. There is no reason to drain this oil! Mobil Delvac 1 synthetic oil is getting good analyses in some trucks at 60,000 miles. How about getting an analysis of your oil at your regular drain interval and let us know how it's doing?...it might be good for a longer interval and save you money. You can still give your truck a good inspection at the time you draw the sample. http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=26;t=000022


Ken

[ February 12, 2003, 02:15 PM: Message edited by: Ken2 ]

 

[cak446]

Ken, I have an older 6.2L diesel. It runs quite a bit dirtier then modern diesels and has a relatively small oil capacity (7 liters). I have done a couple of oil analysis, and determined that 3000 miles is all I can get out of the oil with my driving style, since I drive the truck quite hard. I have recently installed a Baldwin bypass filter, so I my now be able to extend my drain intervals slightly, but until I confirm this with oil analysis I am staying with 3000 mile drains.

In my area I can take my oil, oil filters, and containers in to be recycled, so the environmental effect of more oil changes is minimal.

I agree with the argument that with most engines, running synthetic oil is doesn't cost much more in the long run, due to increased mileage and power. In the August 2002 Hot Rod they tested 65 Mercury Comet that had a 347 V8, T5 manual transmission, and 9-inch rear end. They did some before and after dyno runs with conventional oil and Royal Purple synthetic oil. They gained 10.1 hp and 6.1 lb-ft of torque with the synthetic oil.

I have no problems maximizing oil change intervals, and most members of this board are knowledgeable enough to extend drain intervals safely. However I believe for the other 99% of the population that isn't anal about oil like we are, 3000 mile oil changes with conventional oil is much better than blindly changing synthetic oil at 6000-9000 mile intervals.

Carl

 

[Eiron]

quote:

---

Originally posted by tai:
... if the oil is recycled, and the filter left in, then I don't see much environmental impact. Even considering the cost of recycling, maybe synthetic oil processing products more waste byproducts than processing conventional oil. I don't know.

... In 3000 miles, my car, which gets about 25 mpg, will use 120 gallons of premium. I just need to use 8 gallons less with synthetic to offset the price difference ... That's an improvement in fuel economy of 6.7%.

---

More good points. I've never thought about the waste differences created between the two during refining/processing. Can anybody give us rough numbers on this aspect of oil processing? Let's not forget to add in the cost of "re-processing" a higher volume of conventional waste oil.

I can provide some personal experience with fuel economy. We bought a new '97 Cavalier (27 mi on the odo) & ran Castrol GTX 10w30 up to 20k miles, changing every 3k. The car was used mostly around town, & was getting about 24mpg from the 2.2L 4cyl engine. At 20k, I switched from GTX to Syntec 10w30 & replaced the air filter with a K&N. (Based on the recently-posted air filter comparison, I'd say the K&N added minimal, if any, benefit to the mileage increase.) Changes were extended to 10k miles. Under the same driving conditions, fuel economy improved to 26-27 mpg, or approximately 8%-10%. Around the same time I made the same changes in my '90 Saab with 120k miles. This car was used mostly for commuting (about 300 miles/week), so it was already getting 30+ mpg from the 2.0L 4cyl. The benefit there was significantly less, & only resulted in about 1 mpg improvement, or about 3%. (I now run my Saab almost exclusively on short trips, & its mileage has dropped to the mid-20s.)

Of course, these were not scientifically documented or verified, & obviously only apply to me & my vehicles.

[ February 12, 2003, 05:59 PM: Message edited by: Greg Netzner ]

 

[S2000driver]

If I ran a car short distances I would probably use conventional oil and change it every 2500 miles (myself) . But I don't do short trips at all.

I purchased a car with 140,000 miles on it. Based on the engine condition, the oil was changed frequently. Guess what? THE OIL PAN IS STRIPPED OUT. Lesson: If you are having somebody else change your oil, and frequently, you're likely to be replacing your oil pan, which isn't a cheap proposition. How many mechanics do you think use a torque wrench every time?

Another thing about economics: I can do one synthetic oil change with filter for the same price I would pay a trustworty business to give me a conventional oil change. For this reason, I go ahead and use synthetic.

[ February 12, 2003, 06:47 PM: Message edited by: S2000driver ]

 

[cryptokid]

some good points brought up on both sides, you synthetic guys have made me think about things i had not considered before.

although dyno oil can be recycled, it is still more energy used than if one were to run 9k intervals with synthetic. reformulating used oil takes more energy than just leaving synthetic in your sump for 9K.
then the fuel efficency side of synthetic.

i guess we can all agree then that synthetic *^*should*^* last for atleast 9k in a decent running engine, if dyno can last for 3k.

so at 1.65/qt castrol gtx x4 for an average 4cyl , a decent filter like pur1/wix etc @ around $5 it equals 11.6 dollars per 3000 miles, or 34.8 dollars per 9k.

with a good brand synthetic @ $5/qt plus a good $5 pur1/wix etc it would cost $25 for 9K.

it would be almost $10 less per 9K to buy synthetic, NOT taking into account increased fuel economy, OR the benefits to the envitoment.

AND, if you got your oil analised at that 9K mark, and indeed could drive another 9K, guestimating a $25 analisis charge, it would equal:
$60 at 18K miles (new filter and q/t of oil to replace filter oil)

where as the tried and true dyno oil would cost almost $70 in stuff for 18K worth of miles.

the only problem, is when you blow your third oil analisis on oil thats bad, then its wasted $25 analisation PLUS another $25 in oil for the next 9k.

so, in theory, if you were to just run synthetic for only 9K and change your oil without getting an analisis, you could beat the conventional 3K oil change every time, and be 3 times cleaner to the enviroment. you could just have to bank on the fact that the synthetic would awalys hold up for that 9K without breaking down or anything.

does this make sence to you guys? im startin to think about that mobil 1 right about now.

edit: come to think of it, even if you used el cheapo $1.00/qt no name dyno oil, it STILL would be cheaper to run synthetic!

[ February 12, 2003, 06:57 PM: Message edited by: cryptokid ]

 

[S2000driver]

How much money do you make per hour? Think about how much money you could have made instead of worrying about oil changes.

Don't forget to calculate this into you equation, plus the cost of a hospital visit when dirt from under your car falls in your eye.

 

[cryptokid]

it took me like 8 minutes to figure that out.