Synthetic vs traditional oil?

[purbeast0]

let me just preface this with the face that i pretty much know dick about cars and engines.

that said, i purchased a used 2008 g37s a few months ago and it's time for my oil change according to the recommended mileage (3750).

i have been googling around to see what owners think about this interval as far as oil changes go and i saw some postings about synthetic oil, and how you can go longer with synthetic oil in your car.

additionally, if you do go synthetic, you can't go back to traditional and have to stick with it. but if that is the case and you can go longer intervals, that doesn't bug me at all.

now my main question is ... what is "better" about synthetic oil over traditional oil, and i mean in normal language, not gear head speak, because i wouldn't understand .

additionally, is it true you can actually go longer intervals using synthetic? and is it true that once you go synthetic you can't go back?

i was also contemplating changing my own oil for the first time, as it looks pretty simply. i simply would have to get some tools though in order to do so. if doing this from the ground, do you all recommend just getting a jack and pumping it up to get under the car? or would you recommend some of those little things you can drive up on to that will keep the front tires elevated enough to get under the car?

 

[overst33r]

You can go back and forth as much as you'd like. The only advantage for your naturally aspirated street car with using synthetic is the longer interval.

That's a pretty small interval from the factory. Most cars are 5000mi+ on conventional oil. In your case I would recommend it.

 

[HarryLui]

Synthetic oil is more resistant to heat, molecule is more uniform, less impurity in the oil (take a qt of conventional oil, pour it all out, what do you see in the bottom?), flow easier even if it has the same oil weight number as conventional oil, more resistant to coking, etc.

The only true way to tell how many miles you can go on the oil is to sent the oil out and have it tested.

 

[purbeast0]

You can go back and forth as much as you'd like. The only advantage for your naturally aspirated street car with using synthetic is the longer interval.

That's a pretty small interval from the factory. Most cars are 5000mi+ on conventional oil. In your case I would recommend it.

yea i'm pretty sure they do that just to try to make more money. i mean my old 2004 car i could go 5k miles just fine, and this is a 2008 car which i'd think would be at least comparable, although it's a much more powerful car.

as someone who doesn't race or anything, just used their car for every day driving to/from work (all on highway) as well as errands, would i realistically see any benefit to using synthetic over conventional?

 

[JCH13]

The whole "can't switch oil types" is an erroneous conclusion IMO, but is based on real experiences (as far as I can tell anyway).

It goes something like this: old car has had conventional oil for many many miles, and one day is changed over to synthetic. The detergents in the synthetic oil get rid of the sludge deposits in the engine. One such sludge deposit had plugged a small oil leak in a shitty, worn-out gasket and the engine now begins to leak oil. While synthetic oil did cause the leak in a sense, the gasket should have been replaced anyway.

Back on track...

Synthetic oil is better because it doesn't degrade as fast as conventional oil. HarryLui and overst33r are right on.

To do your own oil changes you'll want:

Jack
4 jackstands (I wouldn't use ramps, it is a good idea to have the car level when draining the oil so that none of the old gets caught in the oil pan or engine and your dipstick reads properly).
Oil filter wrench (unless you've got a cartridge)
Tools required to remove your undertray (if needed)
Wrench and torque wrench to remove and install the drain plug
Oil catch pan
New oil and filter
Funnel to pour in new oil (after the drain plug has been installed of course!)

I always buy oil+filters when Autozone or similar is having a sale on it, which seems like almost all the time.

Do the oil change when the engine is hot, or at least warm (don't burn yourself though). This helps ensure that most of the oil has drained out because oil is less viscous when its hot.

 

[JCH13]

yea i'm pretty sure they do that just to try to make more money. i mean my old 2004 car i could go 5k miles just fine, and this is a 2008 car which i'd think would be at least comparable, although it's a much more powerful car.

as someone who doesn't race or anything, just used their car for every day driving to/from work (all on highway) as well as errands, would i realistically see any benefit to using synthetic over conventional?

I would say yes, over the long term. I believe synthetic oils will help keep sludge/deposits from building up in your engine. But this is just my opinion.

 

[halik]

sythetic

 

[bruceb]

Synthetic is better all around. Car will even start easier in very cold winter weather. Only downside is the slightly higher cost per quart. Walmart has good sales of the 5 qt jug from time to time and this will save you over buying individual quarts. Only thing I would suggest, is stick with a full synthetic and not a synthetic blend.

 

[mvbighead]

Synthetic.

Walmart typically sells the 5 qt jugs of Mobil1 for $26.50 or Pennzoil Platinum for $25 in my area. I've read on the bobtheoilguy site that Pennzoil may do a better job of cleaning out sludge. For me, I've mostly been using Mobil1 because of the name, but as my cars are all older, I am considering running some Pennzoil Platinum ("with advanced cleaning agents") in my 180k mile truck to clean up the engine a bit. Already doing a short change on it with some cheaper dino-Pennzoil and some MMO to clean it out quickly, and then subsequent runs of PP to continue to clean, as well as hopefully keep it clean.

I'd suspect JCH13 is absolutely correct about the reported problems of synthetic. Basically, synthetic has a higher burn point and is less likely to ash, and therefor less likely to create deposits. The way I figure it (and this is just hypothesis), is with dino-oil ashing, eventually a gasket can get covered with deposits. As it gets covered, it is no longer being properly lubricated as the wet oil is unable to get to it. Eventually, it dries out a bit, and cracks. Then, someone starts de-sludging or just switching over to synthetic, and it gets cleaned over time. That spot un-covers, and the crack or wear on the gasket may be far enough through that when the sludge is removed, a hole is left. That's where all the nay-say from synthetic comes from, IMO.

For me, I see the benefits of synthetic as:
1) Longer interval
2) Higher burn/ash point, less likely to build deposits
3) Generally have better cleaning properties, and are less likely (due to 2) to make any deposits
4) Better lubrication in colder temps. (I believe someone did a freezer test with dino and synthetic, and synthetic was quite syrup-y while the dino was basically like a chilled molasses.)

Benefits of dino:
1) Cheaper

For me, if synthetic can make an engine last a while longer, and keep it clean, you should retain more of your engine's original power, and extend its life and the life of the internal gaskets that you really don't want to have to change.

Granted, this is all coming from a guy who just within the last year or so started changing his own oil.

One further addition, I'd suggest staying away from FRAM oil filters. I myself have been using the Purolater Classics as I can buy them at Walmart with the 5 qt jugs of oil, and the price is not much more than the FRAM.

 

[purbeast0]

thanks for the replies.

i think for my first oil change i will just have a mechanic do it. i'm in the process of buying a house and don't have a flat area to change the oil myself now, plus i need to buy all of the equipment (jack and jackstand, which seem to be expensive when i look at the hydraulic ones). so i think i will just do that for my next oil change once i have the house and a flat area in my garage to do the work.

i think for the meantime though i will buy the synthetic oil and take that to the mechanic to do the oil change. i'll also take the oil filter. the quick research i did people simply recommended the nissan oil filters for my car (i'm guessing that is just the OEM one), but would other brands really make any difference?

thanks!

 

[jagec]

One further addition, I'd suggest staying away from FRAM oil filters. I myself have been using the Purolater Classics as I can buy them at Walmart with the 5 qt jugs of oil, and the price is not much more than the FRAM.

Second this. The Purolators are really cheap for what they are.

Lots of people have no problems with FRAM, but the build quality is crap, and they're just NOT worth it.

 

[mike2fix]

If you read up on the synthetics, they do not claim longer drain intervals. There are some exceptions, Mobil 1 Extended, but the highest rated by most, Pennzoil Ultra has info on their website which recommends OEM recommended drain intervals be followed, whatever they may be for the particular make. There have been long term studies done that suggest that over the long haul, recommended drain intervals with dino oil provides the same level of wear protection/prevention as the synthetics. I use full synthetic and have for years but it's more because I'm anal that way and it makes me feel better.

 

[mvbighead]

thanks for the replies.

i think for my first oil change i will just have a mechanic do it. i'm in the process of buying a house and don't have a flat area to change the oil myself now, plus i need to buy all of the equipment (jack and jackstand, which seem to be expensive when i look at the hydraulic ones). so i think i will just do that for my next oil change once i have the house and a flat area in my garage to do the work.

i think for the meantime though i will buy the synthetic oil and take that to the mechanic to do the oil change. i'll also take the oil filter. the quick research i did people simply recommended the nissan oil filters for my car (i'm guessing that is just the OEM one), but would other brands really make any difference?

thanks!

OEMs are fine. I wouldn't get too bent out of shape about which you use. But FRAMs are often referred to as having poor build quality. For me, I like the Purolator for being cheap and good. Wix, the one time I bought it, was expensive. Unfortunately, they were out of stock for what I needed.

As for the jack and such, if you have a local Harbor Freight, you should be able to find a lot of what you need there. I did end up going with a different jack that was recommended to me from some guys on here. Sold at Costco for around $100, it'll get under anything, and lift it as high as you need it to. Arcan I believe was the manufacturer.

As for the level business and 4 jack stands... me, personally, I use two and drain the oil. Add the filter and plug back, and then drop it down, and then add oil. So long as you are careful and get the filter and plug back in correctly, you should never have to re-raise the vehicle to finish the job.

 

[Spicedaddy]

I used to do oil changes myself, now I just go to the dealer.

5 qts of 5W40 Syntec: 35$
OEM oil filter, gasket, drain plug washer: 20$

Dealer charges 90$, so basically it's 35$ more, but I don't have to go buy the stuff, bring back the old oil to get recycled, risk of spilling oil in my driveway, etc. And if something goes wrong, it's their responsibility.

If you DIY, get OEM oil filters.

 

[jagec]

I used to do oil changes myself, now I just go to the dealer.

5 qts of 5W40 Syntec: 35$
OEM oil filter, gasket, drain plug washer: 20$

Dealer charges 90$, so basically it's 35$ more, but I don't have to go buy the stuff, bring back the old oil to get recycled, risk of spilling oil in my driveway, etc. And if something goes wrong, it's their responsibility.

If you DIY, get OEM oil filters.

5 qts of 5W40 better-than-Syntec synthetic: $22
PureONE filter (often better than OEM) $7

Add $1 ripoff price for a new drain plug washer, and we're at 1/3 of the dealership cost. For some people, the ease and peace of mind of a dealership change makes sense, but it comes at a pretty steep premium.

/edit: oops, I thought the Rotella came in 5-qt containers. Make that $27.5 oil cost.

 

[KDKPSJ]

Nissan OEM filter is not that great quality, IMO. I had a chance to take a look at them because they came with my G37 and EX35 (of course!), and I'd say the build quality is probably on par with Fram's. Search the web and Nissan/Infiniti specific forum, you will find many people tend to agree. Some people even cut the new one to see the build quality, and they were fairly disappointed.

 

[Artista]

Synthetic oil is more resistant to heat, molecule is more uniform, less impurity in the oil (take a qt of conventional oil, pour it all out, what do you see in the bottom?), flow easier even if it has the same oil weight number as conventional oil, more resistant to coking, etc.

The only true way to tell how many miles you can go on the oil is to sent the oil out and have it tested.

What he said.

Also you have to use a filter designed for longer mileage use. I use Mobile 1 and the highest Fram filter which is good for 15k. I run it like 7k, then change.

I see a lot of crap in the thread regarding fram filters but minimal evidence to back any of that up. NAPA has the gold standard of filter if you buy their best. OEM pretty much suck, after all they are in the business of making a profit off of a brand name, with crap made in mexico.

If OEM was the best why would there be a market with stuff that much better? OEM is the standard that you do not go below.

 

[jpeyton]

Regular non-syn oil and cheap filter oil change: $25
OCI: 3500 miles
Cost per mile: $0.007

Full syn oil and good filter oil change: $45
OCI: 5000 miles
Cost per mile: $0.009

That's what it really comes down to. Unless you're flat broke and digging in the cushions for change, there is no reason not to go full synthetic plus a good filter (PureOne, Mobil 1, Bosch).

Those OCI's are conservative; if you are light on the pedal, live in a relatively dust-free climate, and do mostly highway miles, you can extend that out.

 

[jagec]

What he said.

Also you have to use a filter designed for longer mileage use. I use Mobile 1 and the highest Fram filter which is good for 15k. I run it like 7k, then change.

I see a lot of crap in the thread regarding fram filters but minimal evidence to back any of that up. NAPA has the gold standard of filter if you buy their best. OEM pretty much suck, after all they are in the business of making a profit off of a brand name, with crap made in mexico.

If OEM was the best why would there be a market with stuff that much better? OEM is the standard that you do not go below.

Lots of websites on the web have cut open Fram filters and looked at build materials, build quality, filter area, and done filtration efficiency and flow tests. Fram is generally poor in all of these areas. I believe that their highest-end series (can't remember the name) is the exception, but why bother when there are so many better-quality filters out there?

OEM isn't always the "best", but it often exceeds the quality at the low end of the aisle (Fram, etc). The reason why there is a market for other filters is because (1)OEM is often very expensive, other filters are cheaper, and (2)Marketing.

 

[foghorn67]

I bought my car used at Carmax, and I have them change it. It's pretty cheap, and they also managed to put on re-branded Wix filters on it. I won't complain about that.

 

[BUTCH1]

I just did mine, I used one QT. fully synthetic and 4 Qts super-tech 5-30. There is so much misinformation and bullshit in oil marketing these days, Quaker State, the "intelligent oil" is so LOL I can't believe people fall for it. Just look at the grade rating your car manufacturer tells you to use and your good to go. I use the one Qt synthetic to help my car cope with the heat here in FL..

 

[Shawn]

Speaking of oil, Has anyone tried that recycled oil walmart has been having sales on. It has been free after rebate for five quarts.

 

[soccerballtux]

You can go back and forth as much as you'd like. The only advantage for your naturally aspirated street car with using synthetic is the longer interval.

That's a pretty small interval from the factory. Most cars are 5000mi+ on conventional oil. In your case I would recommend it.

I'm opposed to the longer intervals with dino. Using Penzoil Gold, at least, I can notice it wear out after about 3000 miles. So I change it then.
However, 3k is too frequent, so I do full synthetic, and then run it ~5-7.5k, depending on how confident I am of the synthetic.

I found a car-synthetic 20w50 that I put into my bike, after 3k it's only just started losing a bit of fluidity so I will probably keep it until 5k.

Pay attention to your vehicle, it's worth it IMO.

 

[overst33r]

I'm opposed to the longer intervals with dino. Using Penzoil Gold, at least, I can notice it wear out after about 3000 miles. So I change it then.

How does one "notice" it wear out?

I trust the engineers that built the engine to determine an OCI. For those that are OCD, there's oil analysis. I haven't heard of any cases where the oil analysis disagreed with the factory recommendations.

My car is a great example. It has one of the most advanced engines of its time. It relies heavily on good oil. The engineers determined a 7500 OCI on dino oil. This was back in the late 90s. The quality of oils has increased since then. Sure synthetic is better, but the notion that dino oil is insufficient and needs to be changed early is a myth.

 

[SyndromeOCZ]

Where can i send my oil to get tested? I'm at 35k miles on this current change for AMS oil full synthetic. I would like to get it tested when I do change it and see how it looks.