alien_rx7

Go with the higher weight 20w50. No experience with how it runs with the 7 yet since I've only owned it since March but I ran 5w30 in an '84 Dodge Daytona back a couple of summers ago when it was super hot (when all those chickens died in Chicago if that helps...) and I think it pretty much killed the engine during the summer driving I did. Towards the end of the summer I started noticing more oil being burnt, what I called blow by, more leaking from just about every orifice in the valve cover (seemed like the valve cover had become pressurized!), when I would pull the dipstick while the engine was running, puffs of smoke would come out of it, etc, etc. So I'm biased against the use of 5w30 especially in hot locations no matter how better the gas mileage is suppose to be.

82transam

iTrader: (18)

When I gave those two examples I was talking about cars in general. I a well aware of the needs of a rotary and change the oil in my 83 every 3k or less. I was just wondering how 3k actually came about cause my parents cars still run great with minimal care. To be fair my Mom saw the dipstick last time I checked her oil and said something like "Holy ****, change that this weekend, that's horrible", can you say sluge? So I'm changing the oil/filter tonight. But still, It's been over 50K since it's last change. THe only reason it was changed the first 2 times was because the first year we got gree dealer tuneups. After that we "forgot" to do it. My dad is just lazy but Honda's are tough cars and last forever so whatever. I didn't want to start trouble on here just pointing out that sometimes things aren't as important as they are hyped to be. BTW does anyone have any good websites that explain the different weights of oil? I guess I should read up on that. Later everyone

85RX7GS

iTrader: (1)

I don't understand why you guys suggest using 20W50 to people who live in colder parts of the country. I use 10W30 year round because I live in that type of temperature region. As for the brand, I only use Castrol GTX on everything I've got. I've been using it for many many years, so why change?

jeremy

iTrader: (1)

well 85rx7gs, we of earth also do not suggest everyone run 20w50 as most have said that they change to 10w40 in fall/winter. i think we've covered just about all bases for decision on this again. 20w50 castrol with 1 qt of mmo in the summer for moderate to hot climates, 10w40 for cooler and cold climates. 5w30 seems a little light, call me crazy. thats my story and i'm sticking to it.

85RX7GS

iTrader: (1)

You're crazy and you're from Kentucky.

mar3

iTrader: (8)

I was running Mobil1 synthetic 10W50 before she was totalled. It went 27,000 miles with no problems, but did seem to start going down on power. I was converted to the MMO flock about 2 months ago and that one addition corrected all the problems the engine seemed to have developed. It now sits in my driveway with 28,600 very hard miles and doesn't smoke at all. The engine will very likely see its third body in the very near future. All of the theories and conjecture around synthetics haven't panned out so far in this engine, but it could very well be that the MMO is keeping the seals from getting stuck by the oil. Who knows?

Tom Delegram

The following is an email and response that I sent to Red Line. In addition, I would recomend that you guys check out their web-site.
To Whom it May Concern:

I am currently in the process of replacing the motor and turbos in my 1994 Mazda RX-7 (Twin Turbo). Mazda recommends that only mineral based oils be used in the motor. I am familiar with your products from the time I spent racing in WERA. I have a great respect for your oils and water wetter. However, I am not sure why Mazda would recommend not using synthetic oils in the RX-7. Could you please elaborate on this? In addition, would you recommend the use of your synthetic oil in this vehicle? If so, based on the following, which product would you recommend:

Currently, I compete in SCCA Solo II every other weekend
One to two track days per month
I always change the oil before 3000 miles usually around 2000 - 2500 miles
I would like to thank you in advance for your timely response.

Thanks again,
Tom


Mazda has recommended only petroleum oils in their rotary engines from the beginning, this seems to be related to problems experienced in some engines.
They had problems with apex seals sticking especially in early engines as well as carbon locking the rotors. These problems are related to poor thermal stability and poor combustion of the injected oil. I don't know if there was actually a particular oil that caused a problem or if it was even a synthetic. The Red Line oils both the Street or Race oils are not a problem, we have used them with good success in numerous rotary engines and just don't have those problems, the oil will burn clean and doesn't cause sticking of the apex seals.
In a new engine I would leave the petroleum break in oil for about 1500 to 2000 miles to allow the seals to seat and the high initial wear to take place.
Once that takes place, I would recommend the Red Line 10W30.
You wouldn't need to change too frequently, we recommend 10 to 18,000 miles or at least once a year.


Regards, Dave
Red Line Oil

82transam

iTrader: (18)

LMFAO

jeremy

iTrader: (1)

but i don't want to be from ky, but i still want to be crazy

thats really interesting tom. i take it you've been doing this and its panned out so far? that would be tops for the lack of work and extra protection if it will work as was said. i might be a convert.

SuperPhly

I don't like the idea of only changing oil every 10,000+ miles... that just doesn't sit well with me... friction is going to happen, shaving are going to come off, and oil will have impurities in it... you need to change your oil... you just do!

BadAssRX-7

Cast. 20-50 in my ported motor going on 45k miles now...and i do a oil change every 2k miles and plugs get pulled and cleaned every 4k

Sterling

...ABSO-******-LUTELY!!!
Among those impurities also being gasoline, an obvious 'break-downer' of earl!
So with that in mind, I don't think it matters too much the brand. My belief is that in a stock, street driven application, just about any ole ****'ll do...so long as it's faithfully changed, or your oil pan seal ...does'nt.

So this does'nt address the 'Synthetic' issue, but what's to be gained by using a synthetic if you're faithfully changing yer earl like a good poochy, anyway?
It'll get damn costly fer one thing...and yer a plain FOOL if you leave oil in the rotary for "10-18,000 miles" - regardless of whether it's "Magic ****" brand synth or not.

I use GTX 20-50, want to use MMO, but have'nt used it regularly yet. Gear **** gets the Redline synth, though I've been eye-ballin' cheeper synths out there, glancing at the lables side by side in the speed shop, going, "Hmmmm. How much different can they really be? Redline costs anywheres from 7 & change to 11 & change a quart! Cheep stuff can be had for $5.

Point being, as I've read some really good oil info **** from a link to a link found on Felix Miatas site, that there really is a difference in dino oils. Some really is just plain ****. But of the good stuff, if you use any of the top 15 or so and change it often, then you should be good.

This plus the fact that your engine will leak fuel and exhaust gases into yer crank, so changing it definitly is in order. If the oil's gonna be saturated with water, fuel, and **** in only 3K miles, then you'll never even get the benifits of using synth, so why blow da dough?

BTW, I won't use recycled oil. That **** ought to be used in furnaces! About all it's good fer. If I was environmentally conciencious, I would'nt own an Rx-7, I'd own a Honda Hybrid.


After everyone finishes adding their "two cents-abilities" to this, we should talk about oil filters here!


http://www.scuderiaciriani.com/rx7/oil_filter_study/

Defprun

I change mine every 1000k. Just because I only had the car for 4000k and I changed the oil at least 4 times or even more than that. Either because it was right after i bought it, or, because it was low from leaking or was because i flooded the engine. Now it has no problems, hell, it runs better than ever!

Directfreak

iTrader: (2)

I only use pure Virgin Olive Oil.

Defprun

ROFLMAO!!!

eddierotary

iTrader: (7)

penzoil 10w-30. for me is the best.

82transam

iTrader: (18)

To clarify: I change the oil in my rex every 3k, My parents are the ones who don't change their oil, I was just saying that their cars still run fine with **** for oil. I am fully aware of the dangers of old oil in a rotary.
LOL@directfreak, that's funny dude

Northern 7

iTrader: (3)

I used to use Castrol 20W50 and switched to Havoline 10W30. Being Canadian and all, the 20W50 was too heavy for cold morning starts - the stuff felt like molassas. A funny thing happened when I switched - I started using less oil (yes, I was burning a little on start up but it would clear up after about 30 seconds). I don't know why and I don't care - all I know is I changed my oil about 1500 miles ago and haven't had to add a drop since (and yes, my OMP is working OK). I also heard 10W40 is not good for Rotarys - too many additives (non-oil like products) and not enough OIL. Mazda recommends 10W30 - mayber they know what they're talking about. One last thing - I noticed my oil pressure dropped a litte with the lighter oil; down to about where it's supposed to be - maybe that's why so many 12A's are smoking - we've blown the seals out with too heavy an oil (just a thought and no factual basis for that statement - take it with a grain of salt and no flames please)

Sterling brought up a good subject on gear oil. Also, because I live in Canada and find myself deprived of many of the great products you Americans take for granted, I was forced to try several other synthetic gear oils in my tranny. None of them did a damn thing for my scratchy syncros - downshifting into 2nd was almost impossible without a crunch unless I was almost to a stop. I finally ordered some Redline MT90 out of the US and that product is remarkable. by the time the stuff landed at my door, it cost me about $20 Canadian a quart - money extremely well spent. I've yet to find an oil, additive, or witches brew that even comes close to standing up to Redline

Sterling

Well when I hear stories like that (and I have before), I figure maybe I will stick with the Redline afterall.
It's not like it gets changed all that often like engine oil anyway, so why experiment just to save a couple bucks every six months?

FuLLsMoKe

Ah... Good thing I didn't decide to use synthetic oil... I always use Castrol GTX 10w-40 and with a side helping of good ole' MMO... I love castrol and it's kept my dad's truck running strong for a good 13 years. But my poor 7 was previously owned by a lazy, good for nothing, cheap, bastard that didn't properly change the fluids in my pooooooor baby! =(
Clutch fluid looked like grease, brake fluid looked like my ****, and the oil was green (not really...).
Now my 7 doesn't smoke, doesn't hesitate, and doesn't groan and moan... It's runnin great--a little TLC goes a long way to make a guy happy =)

jeremy

iTrader: (1)

ok, i knew the avid change your oil party would be here. there is one true statement, contamination. but if you can't tell this when you pull the dipstick then you need to follow the 3k order. otherwise no. like i said, many car companies are putting in a sensor that will tell you when it needs changed. 3k was an idiot device for the blind and uninterested.

the weight 10w-40 has nothing to do with additives. all the 40 means is a heavier winter weight. it will not even affect you any different then 10w-30 at spring/summer temps. additives have to do with brands and lines within a brand.

directfreak- is that **** any good? smoking at start up? slow revving?

Directfreak

iTrader: (2)

Actually it is very good. Last time I took my motor apart all the pieces were clean and shiny with no deposits.

Revs great, smells great, and goes well with Garlic bread.

moremazda

iTrader: (4)

This is not true. Let me break it down for everyone who doesn't know how the labeling works on oil here in America. We will use the 10w-30 lable as the example

10w- The first number in the lable describes the oils characteristics at the freezing point of water. The 10 means that this particular oil will flow as a normal 10 weight oil would at the freezing point of water. The "W" stands for winter.

30- The second number in the lable describes the oil characteristics at room temperature. The 30 means that this oil will flow as a normal 30 wieght oil would at room tempuarture.

Complicated, huh?

So now when people tell you that you should run a thinner oil in colder climates, you should ask why? The operating temperature of your engine doesn't care what climate zone you are in. You don't change your temostat when winter time rolls around. The only time that oil will be affected by the out side temperature, is when the out side temerature cools the oil to, or near the freezing point of water. (IE a cold winter morning).

I hope this helps desypher the oil mystery.

Ryan

peejay

Some people have found that the oil cooler lines tend to blow if you have 20W50 in a cold (sub-freezing) engine and the revs are brought above about 3000-4000.

Food for thought

Personally I don't see the point of running thicker oil... Once over about 3k the oil pressure is regulated. You've not going to see any pressure gains except below that point. However, with thinner oil you'll have more oil flow for a given pressure, meaning better bearing and rotor cooling. Also, thicker oil has more resistance to flow, so even though you may have 85psi of oil pressure at the regulator, thicker oil will have LESS pressure at the bearings than thinner oil because pressure is lost in trying to pump the oil through the passages.

I posted a thread in another section a few months back asking "Why 20W50 oil?" and there were some interesting responses.

the_real_bill

so why not 5w30 then????

thiner oil = better bearing and rotor cooling +
more oil flow

so why doesn't everyone use 5w30 in winter and
10w30 in summer????



why is it that everyone likes to use 20w50??

i just don't get it