Oil change interval with synthetic oil

1. No, an old woman's tale. Complete BS with modern synthetic oils. The early synthetics had different esters and PAO's that would act like a laxative and literally break the deposits loose.

2. Well, that is a touchy subject. The Prius operated in the EU has a normal 12 month or 10,000 mile oil change interval, using ACEA spec motor oils. To maintain warranty Toyota does require you to change your oil and filter every 6 months or 5,000 miles, no matter what oil you use

Considering that my used oil analysis of Mobil 1 0W-20 at 16,000 km was much better than the dealer oil run to only 5,000 km, something is clearly amiss. The dealer oil was also complete crap based on the virgin oil analysis

There have been heated debates on PriusChat over the benefits - and liabilities - of using synthetic oils. Tread with fear!

Given you live in NJ and experience cold winters - not as cold as mine - you would probably have benefits to running a synthetic at least in winter. For winter up here, I prefer to run only a synthetic 0W-30 or 0W-20.

Remember the SAE J300 specs for cold pumping only require a 5W-xx to be "good" down to -30 C. Many will actually test borderline at -25 C

 

Why are you going to the dealer for an oil change? To save $20? Whats wrong with the oil change places that don't even let you get out of your car? Its 5 minutes....as opposed to the circus of taking your car to the dealer for an oil change.. Go to a quickie lube...bring your own Mobil One oil....tell them its 3.5 quarts only.....they show you what they put in..give you back 1/2 quart..give them the factory oil filter its only $6......and $20 and 3 minutes later your out of there. There are all like a machine. Find one you like and always go there. And if concerned check the oil level 1/2 block later. You think the dealer does a better job with your piddling oil change job? Telling the dealer to use conventional oil is nuts. They'll give you conventional oil alright. All for what?...so you can save $ 30? If your so concerned with saving a tiny bit of money why did you buy this car? There's many many new cars for $ 10,000 less that will run just fine and get 30 mpg's all day long. I don't get it. This is not a cheap car.
The last 4 new cars I have owned never saw the inside of a dealer once. I avoid that like the plague. Only thing you have to do is put high quality fluids & oil in them keep them tuned and take it easy on them and most cars will run a long long time. I sold all of them for a profit. I expect to do the same with my Prius.

 

No...avoid quickie lube joints. As for switching, this issue has been raised for 20 years. You may switch at will. No damage will occur. Conventionals and synthetics are completlely interchangeable and compatible, no matter what anyone says.

 

<div class='quotetop'>QUOTE(DougSlug @ Nov 3 2007, 10:31 PM) [snapback]534494[/snapback]</div>

Sorry I thought the whole point of your post was to save money....and yes there are compelling reasons to use syn oil. If you have ever taken a valve cover off of a motor that has run 150k mile on syn oil and has absolutely no dino burn or the dark burnt sludge that you cannot scrape off the metal that says I have run my whole short life on cheap motor oil. A syn oil motor all you have to do is wipe off the oil with a rag and its usually pristene metal underneath. Bottom line its all about keeping it off the dealers rack. Thats a horror and mega $$$$. All you have to do is read posts here for a few weeks. Its full of people that don't pamper there cars and end up on the dreaded rack and wringing there hands that the "DEALER" is trying to screw them out of thousands. Wow..what a coincidence. Quality Oil changes are cheap. Toyota makes a superior motor. All it needs is superior lubrication. I understand that. The dealer does not want you to know that....because the dealer is your enemy.

 

<div class='quotetop'>QUOTE(DougSlug @ Nov 3 2007, 09:14 AM) [snapback]534332[/snapback]</div>

And did they tell you how it could damage your engine? Once again Stealership education at its best. I am amazed they would even say such a thing.....well not really. But no it, won't damage your engine.

 

Why not just change your own oil? It is so freaking easy, takes less time than going to a stealership and will cost you less overall.

 

I owned a VW Passat (1.8 Turbo) that had sludge problems due to poor design -- too small an oil reservoir. Part of VW's solution to prevent the problem is to require the use of synthetic oil. That's just one reason why I have switched to synthetic in every car I own. One bit of caution -- if you plan to run more miles on synthetic than conventional before changing (which is OK), and there is some conventional in the mix from switching back and forth (which is OK), the point at which the conventional would break down is when you need to change, so I stick with synthetic. By the way, I have changed the oil on many cars, and the Prius is one of the easiest.

 

There are issues. The most important is warranty coverage. The Prius owners manual states that oil should be changed every 5,000 miles. If you do not do this required normal maintenance on your car and you have an engine failure, the repair MIGHT NOT be covered by your warranty. You would be at the good/bad graces of Toyota. The Japanese design mentality is the same as the Germans (in my opinion). They have designed and tested the product correctly. Therefore the only way a failure can occur is by customer abuse. At least that is the starting point for warranty service.

In general terms synthetic oil will outperform mineral oil by about say 2.5:1. If the mineral oil is good for 5K miles the synthetic should be good for about 12.5k miles (this is based on Mobil 1 information...I have no other). If the mineral oil is good for 7.5k then the synthetic should be good to around 18k-19k miles. In that mile range you may add a quart or two of make up oil and that would extend the drain interval even more.

But on the other hand if a quart of good mineral costs about $1.25 then the 2.5X life increase for synthetic means you only gain $$ if you can get the synthetic for less than 1.25 x 2.5 =$3.13 per quart. The cheapest I have gotten Mobil 1 for is at Costco for $30 for 6 quarts or $5 per quart.

In all my vehicles that are outside of warranty I use Mobil 1 and change oil once per year or 12,000 miles which ever comes first. I realize that I am paying a premium (see previous paragraph) but I do like the piece of mind. The quart of "oil" contains 3/4 quart of oil the remaining 1/4 quart is all additive package. I do KNOW that Mobil 1 uses an excellent additive package. They do have a premium product. I am paying a premium but I am also really getting a premium product.

For cars still in warranty I change per owners manual and use a good name brand API approved mineral oil. The additive packages in those oils are quite adequate in protecting my vehicles engine. We own a 2008 Prius (5k oil change per owners manual) and 2007 Chev. Equinox (change oil when the Engine Oil Life System has calculated that the oil life has been diminished ( aka: 80% of additive package used up)). For our kind of driving this IS ALSO ABOUT 5,000 MILES!!

I used to drive a lot of Cadillacs with the ELOM and my change intervals were about 6,000 miles. The Cadillacs carried 5.5 quart of oil (at least one quart more that really was 'needed'. If you back that up to the more standard 4.5 quart V8 sump it would have been again about a 5k mile oil change interval. So to make a long story short that is how I came up with the 12k miles (or one year) for changing synthetic oil in my out of warranty vehicles. I feel very comfortable with 12,000 miles and Mobil 1.

 

I have for 30 years, used synthetics with intervals of 12k to 20k miles with not the slightest problem. Dumped the factory fill on my 07 at 3800, added Amsoil with M1 filter and ran 14k mile till I changed. The oil was the same color as when it was put in, and the was no perceptible drop in the level. I'll do the next at 12k.

 

I wouldn't use dino oil in a Prius or anything else. In the Prius, synlube will help your mpg's. I use it in all my vehicles with change intervals of 25,000 miles (or 12 months). I use Amsoil 0-20 with the Ea filters rated for that interval. I have been doing this for over 5 years now and have seen significant savings. As a family, we average over 60,000 per year.

 

"There are issues. The most important is warranty coverage. The Prius owners manual states that oil should be changed every 5,000 miles. If you do not do this required normal maintenance on your car and you have an engine failure, the repair MIGHT NOT be covered by your warranty."

What's to prevent someone from keeping a maintenance log indicating an oil & oil filter change every 5000 miles, but actually only changing it every 10000 miles? This would avoid any warranty claim issues.....

 

Yes it would. I have found that the dealer will generally give you credit for good intention if they stand to get paid by warranty anyway. Regardless of dealer, I have found that the Toyota warranty is very good and very willing to go the extra mile even when they are not sure it is a warranty issue. I have had 5 or 6 toyotas over the years (decades, but who's counting!) starting in 1972.

I will never buy another brand of car the rest of my life if I have a choice.

 

Hey I have a 2010 Prius and I was wondering if jiffy lube type guys will know how to change the oil. I received a free oil change coupon when i bought the car and the guys at the dealership had to read the manual on how to change the oil since it was the first one they'd ever seen (I was one of the first owners of the 2010 Prius).

I agree with not trusting dealerships. They rip you off anyway they can. The main reason people go to the dealership is because of lack of trust in anyone else, so they know they already got you by the balls. I'm just worried the possibly lesser qualified jiffy lube guy will know what to do. I'm not terribly worried about saving money, but I don't want to get a complementary rectum scrub with my oil change if you know what I mean.

 

LOL! Many would say they don't know how to change the oil on ANY car. My suggestion would be DIY, it really is easy and you can be sure it's done correctly.

- D

 

Sounds like you have a GOOD dealer! You should give them CREDIT for reading the manual first instead of just assuming they know everything.:thumb:

 

I'm a newbie here so I'm not sure how popular cross references to other site are so please moderate away if needed.

I have found quite a bit of good information at bobistheoilguy related to lubrication and other auto issues. If you've not been there it's a bit like trying to drink out of a fire hose as far as the information offered. The forum for Passenger Car Motor Oil has hundreds of discussions arguing both for and against Synthetics.

Now to respond to your qustion....
The only way to know for sure when to change your oil is to perform an analysis of the oil by a lab like Blackstone-Labs and OAITesting. I can't post links yet but google these terms and you'll see what it involves. It's too involved and expensive for me but for some folks who worry excessively it offers peace of mind.

With an inconsistent running engine, miles alone are not a good indicator of when to do the change. You will probably have quite a bit of life remaining at 5000 miles if most of your miles are city. My experience with the Prius ICE is very new but if it is anything like the the other small, high precision Toyota and Honda motors, synthetic oils are not needed compared to the new conventional SM service category oils. These engines are very easy on oil and the SM rated oils have an additive package which is very robust. I doubt you or anyone else could pick out the motor in a blind test after 100,000 miles with a good SM rated oil changed every 5,000 miles and a synthetic changed every 5,000 miles or measure any difference in performance. In my opinion your wallet is the only thing that will be damaged with synthetic...but that is my opinion. If you do your own oil changes the synth is not a huge deal from a cost perspective. Some dealer/quickie/service center upcharges for synth are pretty ridiculous in my book.
Don't forget your air filter and how it fits into your oil hygene schedule. The dirt comes from outside the engine through the filter.