I have been using Mobil 1 15/50 oil in my FD. Since I switched, it seems like my car uses a little more oil than with the Castrol 20/50.

I don't want this thread to turn into one of those "Standard VS Synthetic" oil threads. I'm just curious if anyone else has noticed higher oil use with synthetics. If this is the case, does anyone know why?

 

Originally, I started using syn with Mobil 1 15/50. My turbos are leaking slightly as it is and this made it worse for sure.

Switched to Redline 20/50 and my oil leak slowed way down.

I think my oil consumption is actually lower, but hard to tell.

 

OMG....PEOPLE DONT KILL FDS, SYNTHETIC OIL KILLS FDS!!!

GUYS DO SOME REASEARCH....and fush that oil of your cars asap.

 

muzik...lol...dont turn this into a stupid thread. search for synthetic oil and you will see that it is ok to use in our cars now, that is an old out dated rule. things have changed in 10 years.

back to topic....im switchin to mobile 1 in a few days, ill see if i notice a difference.

 

I used to run Castrol GTX dino oil years ago, but switched to Motul 300V 15W-50 synthetic. Besides the smoother idle, improved viscosity/pressure stabilization in high heat conditions, perceived performance improvement, and just overall peace of mind, I haven't noticed an increase in oil consumption in my 57K motor.

 

I switched to synthetic for a few changes and I don't think I saw more consumption as opposed to more LEAKING...

that stuff will come out of places that regular oil wouldn't have a chance at coming out of.

needless to say, I switched back to regular after 2 runs of synthetic

 

Oh, forgot about the second part of Adam C's post. Without going into a discertation on petroleum/synthetic oil chemical composition that will suck up bandwidth, basically dino oils need a bunch of additives to fortify the oil in order for it to pass the continually changing API standards (the little round seal on the bottle that has the letters "API-SJ..."; the American Petroleum Institute is an industry standards organization similar to Underwriters Lab in household electrical products). Most synthetics (I say most, because there are different types of synthetics, which is another story in itself) don't need many of the additives-- or need far less of them-- to pass the API tests. Synthetic oils are just that-- oils that have been made by man-made process, so their molecular makeup is different than dino oils. Part of this results in synthetic oils' ability to seep into and out of cracks and crevices that regular dino oil won't pass.

However, this doesn't mean that using synthetic oil will automatically result in increased oil consumption. There are many other factors involved that can influence an engine's appetite for oil. Too many to list in a short message.

Hope that helps.

 

I switched from Kendall to Mobil 15-40 and yes the oil consumption went up quite a bit. And because I add oil more often now, I'm not too worried if I go a little over the 3k mile oil change because by then I have already added almost 2 quarts. The plus side to it is that there is cleaner motor oil in the engine more often, and that has to be good....

 

F- All that .... Use Amsoil ! Synthetic 20w50 runs great prolongs engine life

 

I haven't noticed any more consumption or leaking since switching from Valvoline to Royal Purple 10W30.

jds

 

OK ONCE AND FOR ALL...

WITH Catalytic Converters- Don't use synthetic

WITH OUT Catalytic Converters- Use synthetic.

 

ahem.

"AMSOIL Motor Oils are formulated with the finest quality synthetic basestocks and additives._ Oil consumption and phosphorus volatility are kept to an absolute minimum, effectively protecting catalytic converters from the damaging effects of phosphorus contaminants, while offering the best wear protection money can buy."

So sythetic oils with low phosphorus content are ok.

 

I have been using Synthetics for over a year now, WITH a catalytic converter. Mondern synthetics burn cleaner than most dino oils, meaning they are even better for the cat than the dino oil.

On to the topic though, I have seen no increase in consuption and dont have a single leak on the whole engine.

 

Is that specifcaly said for rotaries? There have been plenty of these topics, please no more.

 

you are using a lower viscosity oil than you were using before. chances are you have a leak somewhere and because the oil you use now is thinner it may be leaking out somewhere that it had not before.

 

Hard to tell with my oil leak. It does smell different when burning on my exhaust system, though And Royal Purple smells different from the Mobil 1 I was also running...

Royal Purple is quoted on Mazda's own web site (under SevenStock) as saying synthetic is fine for rotaries...we've all been through this before. Even if it is not better for the motor, it certaintly is for the turbos. Take your pick, they are about the same cost (actually turbos cost more but labor more on the motor)...

 

I specifically switched from Mobil1 because it leaked (in the turbos) and my oil pressure readings were consistently low. My dummy gauge is surprisingly accurate, so low oil pressure makes me very nervous. I switched to Redline and was very satisfied. After my second set of rebuilt turbos fryed, I switched to Royal Purple with my new turbos. No leaks, no low oil pressure, no smells from the engine bay or exhaust (except for fuel ... heehee). And I NEVER have to add extra oil. Royal Purple is a dollar and some change more per quart at NAPA than Mobil1, but it's worth my peace of mind.

 

Has anybody tried the Castrol TWS 10W-60 Synthetic that BMW requires for the M3 ? That 60 weight HT viscositicy has to be great for reducing consumption at high speeds. Its $ 10. a quart at the dealer or $9 on-line.

I just checked the Mobil site and they now recommend Mobil-1 for RX-7's

 

That's new(I just checked it out), Mobil 1 didn't use to recommend synthetic in the rotary:

Listed below are the oil viscosities that your vehicle manufacturer recommends for different temperature ranges, as well as the Mobil 1 motor oil that is suitable for your vehicle. You Chose The Following Vehicle:
Make: Mazda (edit)
Model: RX7 (edit)
Year: 1993 (edit)
Engine: 2RTR-1308cc 80 (edit)

10W-30 Above -13° F
You can use Mobil 1 with SuperSyn™ 10W-30 with confidence. This viscosity is also available in Mobil Drive Clean Oil™ and Mobil Drive Clean Synthetic Blend™.

5W-30 Below 32° F
You can use Mobil 1 with SuperSyn™ 5W-30 with confidence. This viscosity is also available in Mobil Drive Clean Oil™ and Mobil Drive Clean Synthetic Blend™.

Be sure to sign up for the free Maintenance Journal service. To locate your closest Mobil 1 retailer or installer, click "Where Can I Find Mobil 1?"


I wonder if they got the go-ahead from Mazda with the intro of the RX-8.

Royal Purple is under $5/quart off of eBay. I think the shop selling it uses the ID RoyalPurpleOil...

 

My oil pan seal leaked a couple days AFTER I started to use Mobil 1 20w-50. I think I'am going to switch to Royal Purple.

 

Guy's Im thinkin' of goin' synthetic, is it ok for a rotary? Also, I want a single turbo converstion with big boost, hugh HP and no lag and be emissions legal, let me know.

Sorry, just trolling through.

 

Okay, now I don't feel as bad. I had to add more oil at around 1300 miles after an oil change. I've been using synthetic for a while now in my FD...I'm going back to the regular stuff

 

Not a good idea. The problem with using such a high viscosity in the rotary (or any viscosity much higher than recommended by the particular engine manufacturer) is that the oil passages and galleys weren't designed to flow such a thick oil. Size of the oil passages plays a crucial role in oil flow and pressure throughout the engine, and you run the risk of poor flow through the oil pump pickup during hard acceleration, as well as proper oil distribution through all areas of the engine.

 

You're SUPPOSED to have to add more oil every 1300-1500 miles or so. That's how the rotary engine is lubricated. I believe the OMP injects oil at a ratio of 400:1 to the gasoline.

I have noticed a significant increase in consumption in going from Castro GTX to Mobil 1. I DO notice that my primary turbo is leaking more oil into the intake passages. I can't state as to the oil pressure since my sender is bit flaky (aren't they all?) and doesn't always read consistently.

 

is straight weight 30 ok?

thanks

-joe