dubulup

I switched yesterday...running real smooth. Is it true you can never go back to dino-juice?

sanfordman

definatly changing to synthetic, my baby is definatly worth the extra couple bucks

sszablya

The old wives tale is that you cannot return to dino oil once you switch to full synthetic. This is absolutely false. Most synthetic oils will mix well with dino when in a desperate situation; I.E. You're out of town, getting gas at some shithole town, you check the oil and you're low; and you didn't pack any spare synth. It's okay to add Dino to keep it running. Just change the oil and filter ASAP.
Keep in mind there are certain synthetic polymers that are designed and sold, premixed with dino oil.
Now, for the myth.. I would stipulate that it is not a matter of incompatibility between the molecular composition, so much as it is a measure of effect. Here's what I mean: The only problem with switching is that you lose the positive effects of the synthetic oil, the same positive effects that you paid $5/qt for. Things like the boundary layer (that ultra thin protective coating on your engine internals that maintains lubrication after the oil is drained), the anti-corrosion, and the operating efficency. While synthetic oil has been proven in some insances to prolong the life of your engine, changing to dino after 50,000 miles of Synthetic could potentially cause one to rapidly lose any of those positive effects accumulated over the past 50,000 miles. It's not like if you switch (back) you motor will blow up, but it's not going to reveal the long term benefits of using Synthetic.

Interesting tidbit: In the early-80's econobox craze, several indepentant testing facilities measured the effects of reduced hydrocarbon emmisions, increased gas mileage, and slower wearing engines when they put synthetic oil in their new motors. The EPA did not want OIL, of all things, to be the factor that pushed the new breed of vehicles into the low-emissions ranks. The EPA proptly rejected the suggestion that synthetic oil be used in the manufacture of new cars, citing that it should be a function of the engine, not the oil, to decrease emisisons, raise power output, and increase gas mileage. Go figure.

yzf-r1

iTrader: (1)

Is it true you can never go back to dino-juice?

old wives tale....syntheitcs and dino juice are compatible/miscible

the only negatives I have heard are that synthetics can accenuate oil leaks, and, in motorcyles, cause increased clutch slippage

I run Mobil 1 15w-50 in my R1....no problems

jmseven

I use Mobil 1 10-40 in my gixx.....love it.

Better to have a slipper clutch....

Street King

Maybe that's why my oil pan gasket leak came into play when I switched to synthetic a while back.......oh well, better I changed it sooner than later.

sszablya

synthetic oils also in many instances contain different detergents, they may have scrubbed the dino oil sludge that was built up/blocking the source of the leak. Engines that run Synthetic oil are typically cleaner inside than their dino-running brothers.

Street King

Yup, I know what you mean. I hope it cleans it all out.

youngteggo

Why are Americans so obsessed with changing oil so often? The rest of the world recomends 6K. Do not mention that it's because they can't afford it or have not been educated as we are.

yzf-r1

iTrader: (1)

becasue they don't know the facts....they are ignorant....furthermore, the vast majority of people don't give a flying rip about maintenace anyway, even if it they did know the facts...they drive a car for 2 years and sell it, they are not enthusiasts

read any SAE publication regarding oil contamination/saturation associated with products of combustion, fuel, and particulate....the 3k rule is based on alot of good scientific data....if you run syntheitc AND you have a high capacity/high efficiency filter/filtration system, you can extend the intervals out to 6k to 8k for a low stress, normally aspirated, low revving vehicle....a turbocharged rotary definitely does not fit the latter category

yzf-r1

iTrader: (1)

this site has some good basic data http://www.motorlife.com/online/yourengine/page2.htm

Street King

Could be trickery. We are the number 1 user of oil. More use = more $$$. But I'll be damned if I changed my oil every 6k miles.

fdracer

so true, they recommend 3k when we pay for the oil, but we had a bmw that had free maintenance, and guess what they would only change the synth oil every 10k.

JUSTgotMINE

if you get an amsoil system they say to change 2x a year. Just have to replace the filter at 12k miles.

RX-Midget

I know this debate is ongoing, so a few months ago I asked Mobil and here is the response I got.

quote:
--------------------------------------------------------------------------------
> Thank you for your inquiry.

> Mazda doesn't recommend synthetic engine oils
> in general for their rotary engines, experience and testing show that Mobil
> 1 provides superior performance in rotary engines.
>
> Technical Support Engineer (WJF)
>
> The above information is provided in good faith based upon the information
> presented by the customer. ExxonMobil is not responsible for any loss or
> damage resulting from inaccuracies or errors in any of the information
> provided or any acts or omissions taken in response to our advice.
>
> Exxon Technical Support: Mobil Technical Support:
> 1-800-44Exxon Prompt #3 1-800-Mobil25 Prompt #3
> (1-800-443-9966) (1-800-662-4525)
>
>
>
> ----- Message from ursnoozin@aol.com on Tue, 25 Jun 2002 17:00:03 +0000
> (GMT) -----
>
> To: mobilproducts@ourdataworks.com
>
> Subject: Mobil1 product Technical
> question
>
>
> I have a Mazda rotory motor (13B, N/A) in my MG Midget. The car is used
> for auto-xing, track days and some trips to the ice cream stand
>
> I want to know if I can use Mobil 1 10W-30 in my motor since it injects
> some of the oil into the combustion chamber like a 2-stroke. Will it
> carbon up the motor compared to std oil? Will it burn clean?
>
> Thanks
--------------------------------------------------------------------------------



It seems that Mobil has done some of their own testing and have found Mobil 1 to be OK. In the past if you asked them (I have), they would just say the Mazda does not recomend synthetic oil. Now they have a new blend of oil (Super-SYN), they say it is OK.

I have now been using 10w-30 Mobil 1 since July 1st. I have noticed cooler oil and water temps(about 5*F), smoother idle, and more power compared to the Castrol 20w-50 I had been using with no bad side effects. I don't have and FD and don't have to put up with the extra heat of turbo(s), but I still think it is good stuff and have been using it in my boingers for years (got 160k on my beater with it since 5kmiles young).


my $0.02

mblachford

Good thread guys. One question - after a fresh teardown/rebuild with new seals, springs etc - should you run Mobil 1 syn from the start? If so what viscosity? 10W30 ?

JUSTgotMINE

No. every syn company will tell you to use dino to break in the engine. It needs a little wear at the start. wait about 3k miles before going to synthetic.

GoRacer

iTrader: (2)

I E-Mailed NEO but no reply. Both Royal Purple and Red Line replied and stated they burned clean and were safe for rotary's.

We used to be told to change oild every 5k mi here in the US. I remember only car enthusiasts, mechanics and so on said every 3k.

Someone else mentioned no oil should go over 3k mi. There is an oil that lasts the life of the car garanteed! Since our cars will burn the oil, it obviously can't last the life of the RX-7.

Does anyone have access to a Corvette or Porsche maual? I'd like to know if it says to change Mobil 1 every 3k mi?

jmseven

Goto: http://www.mobil1.com/index.jsp

Click on the tab "What auto experts say".

Many friends trip on how Porsche uses synthic out of the factory. One of my close friends use to service and modify them. He said that break-in period is true, but Mobil 1 will not effect the process.

CCarlisi

Is Royal purple readily available at autoparts stores? Judging from what I've read it seems like the best choice, but I don't want to get something that will be a total hassel to replace.-the cost is bad enough

RX-Midget

I can get royal purple at a local shop near me, but I'd rather go with something that I can find in any Walmart, Target, or gas station (Mobil). That way if I'm away from home and need it, it is no big deal to find it.

rotorbrain

this in on a porsche. . . . with very superior materials. thats why they cost so much (yes, there are other reasons too. . . i sware making a post in this forum almosts takes a lawyers approval). im not saying that the rotary engine has crude materials, but there is probably a difference in a 35k car and a 90-100k car (or whatever they cost). thats like saying, "well, my buddy jumped off the bridge and he made it." GO AHEAD AND JUMP. . . HOPEFULLY THERE ISNT A GIGANTIC EARTH MOVING CRANE THAT WAS LEFT AT THE BOTTOM OF THE LAKE BY THE STUPID CONSTRUCTION WORKERS AWAITING YOUR ARRIVAL!!! i would still recommend that the break in period is done with dino juice. porsche and other companies MANUFACTURE their engines to perform a certain way and using mobil 1 is how they calculated the results for break-in. the mazda rotary is a different engine using different "stuff" in general. im not downing the use of synthetic in a rotary at all (i use it and will continue to use it), but i would not use it to break in a motor.

just my .02

paul

sszablya

I agree with Paul. Not only is it a different motor, but you'll be changing it at your first 2 500 mile intervals (500, then 1000). Kinda rediculous to spend $5-$10 per quart when you're changing the oil in a few weeks. I'd rather spend $1.30 a quart. the difference (for 2 oil/filter changes+original oil & filter) is $83-$150 for synth+filter or $33 for dino+filter. Use the extra $$$ to go to the IDRC or something.

JUSTgotMINE

I just switched today too. And I have MMO in her too. It does idle a little smoother and I noticed a little higher oil pressure reading. Glad I did it!

TomsRX7

Ok, I've got to throw my $.02 in here:

First of all, for everyone who says "well Porsche" or "well BMW....", those statements and facts are worth about as much as the dirt on the bottom of my shoe. Why does everyone keep using that argument??? Do they have an oil metering pump that injects oil directly in to the combustion chamber? Do they function like a 2-stroke? Ofcourse not.

Now ofcourse, side by side, synthetic is going to out-perform and out-live std dino oil. So yes, your bearings will last longer.

The issue that not too many members seem to realize is the main reason why Mazda does NOT recommend synthetic for the rotary. It supposedly does not fully burn off (like dino does) so it leaves a residue inside the motor. This residue build-up could lead to problems, I don't know. Every rotary I've ever rebuilt, prior to the rebuild I was running Castrol 20/50 and the insides looked great, but I've never rebuilt a synthetic blooded motor to compare any differences. Anyhow, I asked my buddy at Mazdatrix who is their only engine builder, and they build engines for many race teams. His opinion on it was to NOT use it due to the reason I just mentioned.

On the other hand, every rotary builder will have their own opinion. So you guys should ask PERFORMANCE rotary builders like PineApple, and then post the results here. I'm still trying to make this decision myself but so far, I've got one trusted source telling me to stay with dino.

Thanks guys,
Tom