wthdidusay82

iTrader: (15)

Im thinking of getting that idemitsu oil since it just seems ike it would be good for all around performance in my streetported s4 na. Would I get better protection under higher rpm conditions with the 20w50 ? Or would i get the same with a 10w30 ? Just asking because I see alot of people use 20w50 in their cars and alot of ppl recommend 20w50 to me

oh and im not planning on using premix either, stock omp is staying

Turbonut

iTrader: (1)

I'd use the 20/50 during the summer. Below is from the FSM:
10/30 Winter (Temps 0/90) 20/50 Summer (Temps 20/ To Whatever)

TitosToy

let us know how the oil performs. i'm also thinking about using synthetics but i would like to get first hand results from people who've tried them

jhammons01

Why would you be considering an oil nobody has heard of?? I may be out of the loop, I am just cuirious.

ajsuper7

Don't get synthetic oils, it is not any better than the real stuff in rotarys and in the past it caused problems b/c synthetic's don't burn the way the rotary needs. I always use 20w50 in all my 7's. 10w30 is fine but i like the thicker oil. also if you live in a very cold part of the country 10w30 is better for it during the winter.

13btnos

iTrader: (1)

You are out of the loop. Idemitsu formulates their oil specifically for rotary applications check out their U.S. site http://www.idemitsu-usa.com/ it was used in the 1991 Le Mans 26B entry/winner.

wthdidusay82

iTrader: (15)

yeah but it says this oil is made specifically for rotary engines and by an oem supllier for japan, also that it was used in the 787b in the lemans race. im sure this stuff must work if they used it in the lemans car

$150FC

synthetics are better if you're running premix. i'm breaking my engine in with dino oil, though.

Icemark

Please don't push such wrong information... not one synthetic out there that does not burn at or under 500F (with most burning around 400-425F), considerably lower than the combustion temp of a rotary engine.

BklynRX7

The whole synthetics arguemtn is explained in the FAQ (sorry to be one of those people). Basically full synthetics are good, synthetic blends are bad. The reason I wouldnt use such a special oil is because if you get caught out somewhere with car trouble, your not gonna be able to fidn that oil anywhere. I had a hard enough time finding mobile1 15w50. But i know that any mobile station should carry it even if they charge $8 a quart.

bingoboy

if you have any oil leaks, going synthetic will magnify the problem. i'd use the 50 weight if anything just to keep the drips down unless you've got a fairly fresh motor (btw break in needs to be done with dino oil). i wouldn't mind trying the oil out on a car that had the omp blocked off/injectors removed, but i wouldn't want to be injecting stuff that costs $7.50 a quart.

jon88se

This is not true of modern synthetics. I actually believe the RX-8 takes a synthetic oil.

If you aren't constantly beating the **** out of your NA I'd recommend 10W30. You'll likely get slightly better gas mileage as well...

jhammons01

That's really cool!! I like that link especially the one that tells all about Mazda Racing

http://ds.dial.pipex.com/town/pipexd...oc/rotary4.pdf

I'm still going to use Castrol GTX @$2 a quart

I have been racing Castrol GTX almost as long as Mazda has been racing! Well, Since the mid '80s

homebrewer

Neither is a good choice since synthetic oil in a rotary engine are a WASTE OF MONEY. Syn oil has only 3 advantages over dino oil:

1. Better pour point and flow characteristics in cold temps. Not an issue for most of us drivers who don't live in Alaska

2. Better protection at extreme temps (same temps would destroy other engine components anyway)

3. Extended oil intervals due to significantly higher TBN of syn oil. With oil injection, extended oil change intervals are not relevent.


Gee, my FSM says 10w-40 is a good year round viscosity to use but for some reason you guys are scared to recommend it. I never had any problem using 10W-40 in my 86 RX7, in my 90 Black Vert 150,000 miles, my 90 Red vert 112,000 miles, and my newest baby, my 1991 Red Vert w/ only 22.5k miles.

10w-40 has less viscosity index improvers than 10w-30 oils even though the viscosity spread is higher.

As for syn blend not good for a rotary? Hogwash...the 5W-20 oil used in the Renesis is a Group III and Group IV bacestock oil blend. Group III basestock is a severely hydrocracked oil and Group IV are PAO (synthetic).

All of this talk about oil is hilarious since many of you appear to blow an engine every other week. I'm disappointed since I have yet have one blow on me yet but my black vert was starting to smoke a little on a cold start.

jhammons01

That's a good one. I have never blown a motor. I always buy cars on their last leg because I am cheap. so yes I usually rebuld the motor and mostly everything else on a car that I get.

I raced Two years on My KX125 with the same Piston and rings. Always, Castrol GTX 20-50. My Brother however, Had a brand new bike and needed new top end four times in the same period of time.

New to the RX7 Scene, looking around those that build and Race RX7 and Whoa, they say to use.....Castrol GTX 20-50 HHHMMMMM

http://www.mazdatrix.com/faq/synthetc.htm

don't like just an opinion, check out his videos The guy does hold the fastest lap record at Buttonwillow........the FASTEST lap For all cars not just Mazda

Icemark

I think you have that backwards... the viscosity index improvers (polymers) are turning a 10W base stock into a 40 weight when warm add considerably more long chain polymers to the base stock than a 10W30.

10W40 and 10W50 conventional are no longer recommended by the majority of auto manufactures for higher reving motors. In fact several companies (including two of the worlds largest automotive manufactures) will void or attempt to void any of their products that 10W40 or 10W50 oils are used in. Toyota has sent TSBs to dealers mandating dealers to no longer use 10W40 and 10W50 oils as they have been proven to cause slugeing issues in their DOHC V6 engines. Those are simple under 6000 RPM V6 engines... can you just imagine what happens in a rotary that is taken to 7K or 8k regularly (as one should take the rotary to redline).

Maybe this will help: http://www.vtr.org/maintain/oil-overview.html

Look at the increased Ash levels in the 5W30, 15W40, and 5W40 oils (all simular in additive packages to the dreaded 10W40 oils)... Increased Ash levels mean increased deposits on a rotary engine.

Now compare the pour temps, (refering back to the linked page) notice how there is not much better numbers for using the 15W40, and 5W40 (and even 5W30) oils over the conventional 10W30 or 20W50 oils... so there is no advantage what so ever in using the a conventional 10W40 or 10W50 oil, but there are some radical dis-advantages.

cendo54

iTrader: (2)

looks like 20/50 castrol's not too bad, especially for us here in hawaii. thanks for the link icemark!

Gene

iTrader: (1)

Whoo that idemitsu stuff is expensive. Their premix oil isn't priced badly though, and the low recommended 1/2 oz per gallon means you don't use that much of it.

What's the verdict on mobil 1 15w50 synthetic in a car with no OMP?

vice

wow, i had no idea there were other people in america that knew about idemitsu! they are the biggest oil company in Thailand's(my home) motorcycle scene. I build bikes when i am there and use nothign but idemitsu. i would definantly use it her too if i could easily get a hold of some.

jhammons01

I just saw an add in RXtuner (way old issue, summer '04) for that stuff. They now have TWO outlets in the USA. HHMMM Two outlets......in the whole USA.

andrew lohaus

its not like you cant pour a quart of dino oil or a different kind of synthetic into the engine if you need to top it off and you cant get your hands on whatever this exotic japanese sythetic oil is. sure it wont be ideal, but you'd be a moron to not have the proper amount of oil in your car cus you were waiting for a case to get shipped in from overseas........

Mint87RX7

how do you think idemitsu compares to amsoil and redline? i need to find some good premix to start ordering because all the auto places around here just carry crap 2-cycle.

andrew lohaus

all tcw-3 premixes are baisically the same thing. heck ive used some lawn-mower 2-cycle oil a few times and i think my car actualy ran better........
at the rate it gets used up, there is little point it forking out lots of $$$ for anyhting more than your standard tcw-3 which is less than $10 a gallon at wal-mart.

boosted1205

iTrader: (9)

Oil is all a matter of preference. If you want to spend $10./ quart then all the power to you. It's your car and no one should bitch and moan about you doing so. Some people here gets their panties all in a bunch when there's something they don't agree on. People screaming "SYNTHETICS ARE BAD!!" should relax. You aren't rotary engineers. I sure am not one but a few years ago I had an unfortunate luxury of tearing apart a motor running AMSOIL 20W50 9,000 miles and there were very very small amount of carbon. The internals were clean. There were some slimy substance due to synthetics not burning completely. That's minor. I changed to pre-mix. Problem solved. Only full synthetics can give you high pour point, high viscosity index AND very low ash.
All modern synthetics are high quality oil. There should be no reason for you not to use it. If you can't afford it, use quality oil and change them often. Did you ever see the oil injector holes in the rotor housing?? It's about the size of a pin head. You don't want that clogged. I'll say it again, CASTROL GTX 20W50 is NOT a low ash oil.

I'm using TORCO 20W50 now. No complaints.

Mint87RX7

I was just wondering if anyone knows what the best premix is. not for everyday, gas is expensive enough without $10 premix per fill up. i just like to use some quality oil for "beat the **** out of your car" days like autocrosses