Toyota Service Said Don't Switch to Synthetic Oil

That just reinforces the idea that "service writers" may not know anything about the cars that are being serviced. He may have read something about high oil usage after converting to synthetic in the past and didn't want you coming back with a complaint.

 

I would not change to synthetic now.....your engine was not designed for such a thin oil. If you put synthetic in it.....there is a real good chance that it will leak oil where it never has before.

 

If you're in the mood to experiment, give it a shot. Keep track of any mileage differences and consumption. If it all looks worth the extra expense, fine. If not, switch back.

 

Um-- Synthetic oil comes in a wide range of viscosities. There's no reason to assume synthetic = thin.

 

If you've been doing regular oil changes and the engine is currently clean and in good condition, then switching to synthetic is very unlikely to cause any problems. Use a 5W30 synthetic and just watch it closely for any extra oil consumption during the first one or two oil change intervals.

I used full synthetic for the first time in my Prius about about that same mileage and had no issues at all.

 

Oh contrare.....This engine was designed for very thin oil. Not to many oils thinner than 20 weight which is what Toyota recommends.
55,000 is nothing on a modern engine.

Put 3 1/2 quarts of Mobil 1 in there and the car will love it.
You will have doubled the life of the engine by moving over to synthetic. And it will save you time, money, hassle, and oil as you can extend the oci to at least 7500 miles as you planned.

 

you don't live in the north so switching to synthetic will not yield you the easier cold weather starting that it does for us northerners, synthetic oil lasts about twice as long as conventional oil, but doing that at a dealership where they will use a regular oil filter is silly because it will get clogged up in just 7500 miles of driving, you need to use a hi capacity oil filter, such as Mobil M1-103 or Fram XG4967.

In other words, use oil and filter that are both designed for 7500 miles, or use oil and filter that are both designed for 15000 miles, I personally don't waste time with the Mobil filter and Mobil Extended Performance oil, that adds up to almost $45 DIY for 15,000 miles of service. Instead I've always like Pennzoil Platinum (yes I know their conventional oil is absolutely garbage but their synthetic is quite good) with the Fram Extended Guard filter, which is only $35 DIY, and lasts me 13,333 miles.

Doing the math Mobil oil and filter will cost me $360 for 120K miles whereas Pennzoil Platinum Oil with fram filter only cost me $315 over that same period, and fram oil filters often have rebates when you buy them with an engine or cabin air filter which makes them an even better value.

Fram makes oil filters in 3 grades, the extended guard I was talking about, a lower grade and a medium grade as well. The lower grade is for older cars that use conventional oil changed every 3K miles, the medium grade is for newer cars that use conventional oil changed every 5K or 7.5K miles. I can't guarantee it but I would bet money that their medium grade is cheaper and better than the toyota oem oil filter, not to mention Walmart is much for convenient for most people than the dealership.

 

I switched our Pilot at 59,000 miles to Synthetic when we bought it. I am certain it had dino oil used in it up to that point. It now has 120,000 on it with no leaks or oil consumption. I would not hesitate to change another vehicle over with similar mileage.

 

that was funny... thnx for the laugh!

the only concern would be that deposits from dino would get flushed and will clog filter. That will open bypass filter and will destroy main bearings in 5min or less.

My mechanic advises to change oil filter 500mi after oil switch and add oil to the level (~1qt on most engines). He also advises not to use high efficiency filters and go with oversize one if available. I'd use Bosch distance plus it has high holding capacity.

 

The only problem with that logic is that in the UK and much of Europe the standard dealer OCI is 10k miles and yet they still use the same OEM filters.

The fact is that it's hard to find solid data on just how long these filters can last, so it is difficult to know exactly what is the filter life. I'm sure however that Toyota engineers have access studies/data on filter life and I'm certain they wouldn't be approving 10k mile oil change intervals in the UK if the filters were gone by 7.5k.

I did once search for solid data on exactly this topic and it was hard to find as most of studies seemed to be propriety. I did manage to get one study (unfortunately in Finnish) and with a bit of help in translation was able to learn that typical passenger car filters were able to collect between 10 an 30 grams of wear metals before they really started to restrict flow, with the mean value being around 14 grams (half an once).

Now I don't know exactly how much wear metal an engine in fair/good condition produces in 7.5 k miles but I can tell you one thing for sure. If they were shedding 1/2 once of wear metals internally every 10k miles then you'd be hard pressed to find a single vehicle on the road with 100k miles on the engine, let alone the 200k and even 300k miles that we often see.

 

uart (or anyone else who has done this):

When you switched to synthetic oil from dino oil in your Prius --- DID you REALLY see any increase in your mpg??

 

There may have been a really small increase but honestly it's difficult to say.

Prior to the change the dealer was doing the oil changes and I'm not even 100% sure what viscosity they were using. When I took over oil changes I used only a semi-synthetic (Valv Durablend 5W30) on my first change and there may have been a tiny increase in FE there. Next change I used a full synthetic of just about identical viscosity and I don't think I noticed any significant difference.

 

I see no problem switching to high quality synthetic such as Mobil-1.
Suggest go to MobilOil.com. They give many answers to the questions being raised here.

^^^MPG is only increased if you purchase higher MPG oil (eg; 0W-30) and I assume benefit is modest; claim is up to 1-2% better.

Possibly there are generic brand synthetics of lesser quality, so I would stick with the higher quality brands. That is Mobil-1 for me but other brands (AMSOIL?) also high qulaity.

 

Just use the proper weight oil. I went synthetic on a 1965 mustang without issue on the advice of dozens of old and muscle car owners. Why better lubrication and no sludge. Here come the naye Sayers. I'll just listen to the motor guys I trust who open dozens of engines a year and compare the ones using Dino vs synthetic. Every engine I own gets synthetic but it's your choice. I have been using synthetic since it can on the market in retail stores.

 

I use synthetic oil in all my cars so that I can stretch the oil change frequency longer. I usually push to 15,000 miles per change. Never had any problems.

Not sure what your service advisor is talking about. But he's using a common tactic that you seem to have fell for. They'll down sell you on an item (usually one that they dont make too much money or commission on!) to build trust and will up sell you at another time once they got you on the hook! he just hasn't wheeled you in yet.

 

If you only get 1% improvement in MPG by going to synthetic oil, over the life of the oil it pays for itself in other words free oil changes.

 

since synthetic lasts x2 times longer, the cost per mile is about the same as conventional. Not sure for MPG but the real savings come from longer engine life. I have a '96 Mazda with 380,000mi.. would never gone that far on conventional oil

 

Nope.
3.5 quarts dino oil at $3. a quart: $10.50
3.5 quarts of Mobil 1 at $7 a quart: $24.50

Mobil 1 lasts 10K miles no problem so given that dino oil is good to about 3K miles go 3.33 times dino oil to meet the Mobil 1 10K . That's $10 more than Mobil 1 just for the oil plus the time lost and the hassle and the labor charge having to change the oil 2+ more times than a Mobil 1 change. That's pretty substantial given that for some people that exposes them to a Jiffy lube or two and its horror.

It really adds up.

And as you post states even at 10K Mob 1 is still better for your motor. I have torn down a motor or 2 that has used Mob 1 since new and its impressive.

In fact in a Prius I think your better off running Mobil 1 for even 25,000+ rather than using dino oil changed out every 3K miles.