conventional oil vs synthetic

So this just occurred to me today, my whole life I have heard that once you switch an engine to synthetic it is a bad idea to go back to conventional.

But I have never been told why that is a bad idea


reasoning?


conspiracy theory?

 

It is a bad idea to use conventional in the first place.

Why would you want to switch back


But seriously, you can go back and forth, and even mix them as long as you treat the resulting blend as a non-synthetic.
There are no down-sides to running synthetic other than cost.

 

because I am a poor college student

why is it?

(not trying to argue, Iv long ago accepted that synthetics are better but im trying to understand why.....beyond conspiracy theories)

 

Totally understandable

Better film retention, lower cold-pour point, better resistance to coking, (coking leads to sludge formation), better resistance to viscosity breakdown, better viscosity retention at higher temperatures.....

People always talk about extended drain intervals.
That's an easy one to point to because it makes the higher cost easier to tolerate, but it really isn't that big of an advantage on normal vehicles.
On large fleet vehicles, you are talking about several gallons of oil per change, so it becomes worthwhile to invest a couple of hundred $$ into a good bypass filtration system, and to send out used oil samples for analysis at a cost of $25 or $30... the lab will tell you when you need to change your oil.
For the rest of us... I change the oil in my wife's Rav4 at 7500 miles, and I stick to 5000 for the Tacoma. I use nothing but Mobil-1 5w30.

It costs a little more, but since I do my own work, it's no more expensive than someone taking their car to the shop and getting bulk oil and a mystery filter.

 

college town....no walmart....

thanks for pointing it out....now Im that kid in the class that just got glasses and everyone laughs at




guess i thought synthetics were more expensive than that though, I will look around, I can probably find something

anyway, back on track, why are synthetics better for an engine?

 

LOL!

In your position, I'd just stick with Castrol 5w30 and change it every 5000.
http://www.partswebsite.com/1sttoyo...tid=10020&subcatid=20099&section=1&type=parts
$88 will get you 20 OEM filters.... 100,000 miles

 

It's actually 28 doll hairs

 

College town with no walmart? Whaa? I just dropped my taco off for first oil change at 4600 miles. Guy tried to tell me it was every 10k, soon realized he was wrong. Willing to bet they load me up with conventional, so as far as switching back and forth and how misinformed some of the service writers are, im sure many trucks taken to dealership for their free oil changes end up switching back and forth anyway. Bummer :/

 

A truck owner that does not do his own oil changes? Whaaa?


so....nobody knows why synthetics are better?

 

Did you miss this?

 

My dealership gave me a little booklet with my license plates that says "your truck came with 0w-20 synthetic oil from the factory.". I bought a v6, it had 5w-30 dino in it. You're right, they arent very smart.

 

To the comment of 'truck owner who doesn't do his own oil changes?', this was the first time I've NOT done an oil change on any of the vehicles I've owned (5). Reason? It was free, and I'm working more than before to afford things like a new truck - not as much time to monkey around outside in 100* heat. I also would like to have documentation of work done instead of just a receipt for some oil I got at wal-mart. Oh yeah, tire pressure check and rotation, fluids topped off.

Anyway, that was the last one ever. As I mentioned, the service writer initially tried to tell me the interval was 10k miles on the 4cyl. After he was corrected, I emphasized synthetic so much that he typed it in three places on the work order. When I got the truck back and took a look at the final paperwork, they used 5w30.

I pulled in to a gas station a couple miles later and popped the hood. Oil was all over the valve cover and down the front of the block, looks like they narrowly missed the alternator with a big glop of oil. I checked the level and couldn't really see a defined level, typical of this dipstick and all I know. I opened the oil filler cap for shits and giggles and a nice curl of smoke or vapor came out, not sure which but not a fan of seeing anything come out after a 2 mile drive from dealership to gas station.

Checked the level this morning after it sat overnight (got pretty cool out) and could see a little better. It's just barely above the low notch.

So, fuck em. Sucks that I'm now going to have to pay to get oil changes because they can't be trusted - I was looking forward to letting them do everything with pricey toyota oil and filters :|

 

Toyota filters are not pricey.

http://www.partswebsite.com/1sttoyo...tid=10020&subcatid=20099&section=1&type=parts

$88 shipped will get you enough filters to last 100k.