I was getting and oil change today at the dealer ship. I got valvoline premium 5w20 but the guy at the front desk said 5w20 doesn’t cut it, I should have pot 5w30. He said it’s better for the car. So I was wandering if that’s true. And also I was ganna change my transmission oil but I can’t decide between royal purple Max-gear 75w90 or redline MT90. :uhh:

Redline, there have been lube failure issues with RP.

S

5w-30 is better, 5w-20 is thin

wow the guy at the dealership knows his stuff. lol

Redline, there have been lube failure issues with RP.

S

really?

did not have that problem..

45k miles. but i dont shift like a ham!!! :)

beers :beer:

. I got valvoline premium 5w20 but the guy at the front desk said 5w20 doesn’t cut it, I should have pot 5w30. :

did this guy have a pic of a hambuger on his T shirt by chance ?

redline MT90 for tranny, for rear diff u can use maxgear or RL 75w90 or Mobil1 75w90.

and at LEAST 5w-30 for motor

the dealership guy actually know his stuff ... or maybe he know he has too much 5w-30 in the back room and need to get rid of it ? ... who knows :)

ah nycgps - the very person I was talking about .....

lol thanks you guys, ill switch things up on my next oil change. You guys recommend any specific brand?

Castrol GTX. Unless you've got a T-shirt with a Big Mac on it, in which case you'll rotate between every known brand and weight of synthetic oil. :)

Ken

This is what is in my Mazda Manual....so not a problem...I had to show the Mazda-mech and thats all he needed. Some of us should be running 10X40wt or even 20X50wt in hot climates. What is your location? Does it get hot there?

"Engine oil viscosity, or thickness, has an
effect on fuel economy and cold-weather
operation (starting and oil flow).
Low-viscosity engine oils can provide
improved fuel economy and cold-weather
performance.
But high-temperature weather conditions
require higher-viscosity engine oils for
satisfactory lubrication"

5W-20 is thin. I use 5W-30 all year :)

I was getting and oil change today at the dealer ship. I got valvoline premium 5w20 but the guy at the front desk said 5w20 doesn’t cut it, I should have pot 5w30. He said it’s better for the car.

Wow, that's a new one. Never heard of a Mazda employee going against the party line, especially with 5w20 engraved on the filler cap. :eyetwitch I've heard plenty of times where they will ignore the recommendation and use whatever is on hand, but never heard of them recommending against5w20. Maybe they didn't give him all his shots yet. :lol:

A lot of people believe in using one grade heavier oil than auto manufacturers specify, no matter what the car. When my wife bought her Camry, the head of the service department said that they always go one grade up.

Nice to know that so many people remember Tom McCahill's teachings. :)

Ken

I have a failing motor and losing compression. Before I've been using mineral 5W30 Mazda Oil. I've been having to change the oil every 3000Km to keep the engine running smoothly. I went to an outside mechanic and they recommend I give 5W50 or 5W60 Ultra Synthetic (didn't knowthere were oilds that thick) a try; since right now it seems that when I have new oil in the car it performs correctly and once I get the 3K or 4K KM mark the engine starts to stall after hard driving. So they think if I use a thicker oil like those use on cars with turbos maybe it might last longer between failures. Do you guys think this is correct?

I have a failing motor and losing compression. Before I've been using mineral 5W30 Mazda Oil. I've been having to change the oil every 3000Km to keep the engine running smoothly. I went to an outside mechanic and they recommend I give 5W50 or 5W60 Ultra Synthetic (didn't knowthere were oilds that thick) a try; since right now it seems that when I have new oil in the car it performs correctly and once I get the 3K or 4K KM mark the engine starts to stall after hard driving. So they think if I use a thicker oil like those use on cars with turbos maybe it might last longer between failures. Do you guys think this is correct?

Judging from the fact that your location is in Taiwan, you have the 4 speed AT, '04 or '05.

Wasn't there a post about 4 speed AT with one oil cooler which contribute to failer in hot climate such as CA, AZ, NV? Need to do a search on this, but that's what was speculated as reason that '06 6 Speed AT has two oil cooler.
Since higher oil temp. causes oil to break down quicker, and Taiwan weather is similar to west coast region. That's what I suspect anyway as the reason...

Yes, I have a '04 4spd AT. Wouldn't be able to add another oild cooler right? Or should I replace it with a better after market heavy duty one. Do you think that might help prolong the engine's life. It get very hot in Taiwan typical summer temp is around 100-105 F. So maybe if I get a heavier weight rating oil like 50 or 60 then I might be able to solve this problem and run this motor a little longer.

^Oh shit! you only have one? Get a second one asap or you will be needing a new engine real soon. Talk to your dealer, they had a Mazda tech add a second one to my AT for free.

I think it is possible to add a second oil cooler (I think RE-amemiya makes oil cooler for RX-8), but you might want to check AT performance mod forum on that...
IF it is possible, it will likely slow down the oil breakdown, assuming high temperature oil breakdown is the main factor.

Also, not going to start synthetic/dino oil debate, but something to keep in mind if the 5W-50 and 5W-60 are synthetic, you might want to think about how well they burn, since it is also being injected to lubricate apex seals.

I think some people uses 20W50, they might be able to give you a better idea regarding using XW-50 or XW-60.

Have you given premix some thought (synthetic 2 cycle with at least JASCO FC rating)? That should help lubricate the seals.

*shurgs*

If I were in Vegas I'd be running 5w-30 all year too, but we're already into Fall temps here and 5w-20 is just right. I do premix 4 oz of Idemitsu / tank tho'.

the point of using higher grade is to increase its film strength.

Our engine will operate at very high temp, 5w-20's film strength is simply too weak to prevent metal metal contact.

it doesnt matter if you premix or not (better if you do), but if the internals gonna rub against each other, no good.

Yes, I have a '04 4spd AT. Wouldn't be able to add another oild cooler right? Or should I replace it with a better after market heavy duty one. Do you think that might help prolong the engine's life. It get very hot in Taiwan typical summer temp is around 100-105 F. So maybe if I get a heavier weight rating oil like 50 or 60 then I might be able to solve this problem and run this motor a little longer.

Sounds like you may have some compression issues due to carbon buildup and insufficient oil metering. I would recommend a de-carbonization and running a little 2 stroke pre-mix with every fill up of gas (Petrol) as a first approach.

For the added oil cooling I am proud to offer this factory original Mazda R oil cooler kit for the best price any where: http://www.mazmart.com/PartsList.aspx?id=27&n=NEW&m=6. As a matter of fact, I'm the only place that sells this comprehensive kit.

Paul.

5w-20 "film strength" is plenty adequate.

Our rotaries actually run cooler (less thermal mass) than piston engines, which is why we get poorer gas mileage. 5w-20 slightly aids better gas mileage due to its relative thinness.

The point of pre-mix is to augment the existing oil-to-seal system.

Moving to 5w-30 in very hot climates is a good idea tho' to avoid viscosity breakdown.

This whole discussion is a bit academic if you change your oil every 3k miles, as I do.

the point of using higher grade is to increase its film strength.

Our engine will operate at very high temp, 5w-20's film strength is simply too weak to prevent metal metal contact.

it doesnt matter if you premix or not (better if you do), but if the internals gonna rub against each other, no good.

^ rotaries run cool? since when? I use 5w30 but prob next summer will run 10w30 and 5w30 in the "winter"

Our rotaries actually run cooler (less thermal mass) than piston engines.

Huh? We produce the same power in a smaller volume of space. From where comes "cooler"?

5w-20 "film strength" is plenty adequate.

Our rotaries actually run cooler (less thermal mass) than piston engines, which is why we get poorer gas mileage. 5w-20 slightly aids better gas mileage due to its relative thinness.

The point of pre-mix is to augment the existing oil-to-seal system.

Moving to 5w-30 in very hot climates is a good idea tho' to avoid viscosity breakdown.

This whole discussion is a bit academic if you change your oil every 3k miles, as I do.

I have to disagree with you here.

5w-20 offers weak ass protection, thinner = weaker strength = easier metal to metal contact = no good. Only good thing about 5w-20 is you probably get like another couple % better mpg. thats about it. You're pretty much giving up engine life for if "you can notice" mpg increase.

Even Castrol admits it.

Engine life - Something = or higher than 5w30
Every single bit of MPG - 5w20.

5w-20 should not be used if engine life is your major concern.

Plus, since when did Rotary engine runs cooler than piston cousins?

Come on guys, we all know there's less thermal mass in our rotary than a comparable power piston engine. Again, one of the reasons we get poorer mpg.

I'm not saying 5w-30 isn't better, but we need not scare off folks who go with dealer mandated 5w-20. Better to have them change oil frequently.

Oh, and I go Castrol GTX as well.

I have always used Castrol GTX 5W-30 all year round redline 1st 2nd and even 3rd on the freeway on ramps use ide premix and have no carb buil bup that I can see coming out the back of my exhaust. That dont mean its not building up inside my engine.

Come on guys, we all know there's less thermal mass in our rotary than a comparable power piston engine. Again, one of the reasons we get poorer mpg.

I'm not saying 5w-30 isn't better, but we need not scare off folks who go with dealer mandated 5w-20. Better to have them change oil frequently.

Oh, and I go Castrol GTX as well.

Did you not read your manual....show it to your dealer!

"Engine oil viscosity, or thickness, has an
effect on fuel economy and cold-weather
operation (starting and oil flow).
Low-viscosity engine oils can provide
improved fuel economy and cold-weather
performance.
But high-temperature weather conditions
require higher-viscosity engine oils for
satisfactory lubrication

My 2005 manual specifically cites "5W-20" on page 8-13, so showing it to my dealer would be pointless.

So I don't and change my own. ;)

Doesn't your manual also say "or 5w30 under certain circumstances?" or words to that effect ?(your manual is different from mine)

I thought it was mentioned.....

S

The manual also tells ya that, it really depends on your local condition, and you can use anything that fits your area.

Come on guys, we all know there's less thermal mass in our rotary than a comparable power piston engine.

Still not sure what you mean by that. The engine weighs less, that's true. That in itself doesn't necessarily make it cooler or hotter so I'm not sure what you're getting at with "less thermal mass".

The Wankel engine produces remarkable power for its size (mass) compared with piston engines. However, that relatively small mass is also a disadvantage as all internal combustion engines are more efficient when fully warmed up (e.g. highway speeds for long duration). There's plenty of thermal dynamics info out there on the Wankel and its effect on gasoline efficiency.

Interestingly, at one point the Wankel was able to pass emissions regulations w/o a cat, but at the expense of even more fuel consumption. Perhaps we'd all be happy with 10 mpg but no cat. ;)

Still not sure what you mean by that. The engine weighs less, that's true. That in itself doesn't necessarily make it cooler or hotter so I'm not sure what you're getting at with "less thermal mass".

Doesn't your manual also say "or 5w30 under certain circumstances?" or words to that effect ?(your manual is different from mine)...

Page 8-12 of my '06 manual has a paragraph headed "Recommended Oil." The first line of the paragraph, in bold, says "Use SAE 5w20 engine oil." The pictorial with the thermometer shows 5w20 for all temperatures. There's no waffling about it, no discussion of situation dependence.

So the manuals do change from year to year.

Ken

Page 8-12 of my '06 manual has a paragraph headed "Recommended Oil." The first line of the paragraph, in bold, says "Use SAE 5w20 engine oil." The pictorial with the thermometer shows 5w20 for all temperatures. There's no waffling about it, no discussion of situation dependence.

So the manuals do change from year to year.

Ken

that also means they're just generalizing it.

the rule is, use what you want.

that also means they're just generalizing it.

Or taking a bigger swig of Kool Aid.

the rule is, use what you want.

Gasp! Not follow the manual? After Mazda went to all the trouble of printing it? Not just once, but a revised version every year?

Ken

Or taking a bigger swig of Kool Aid.



Gasp! Not follow the manual? After Mazda went to all the trouble of printing it? Not just once, but a revised version every year?

Ken

They change their warranty as well , at least for Basic warranty :P

04-05 50 K miles / 48 months

06+ 36K miles / 36 months :lol:

they probably found out "aww crap 5w-20 is craping our engines, lets make the basic part shorter so we carry less liability" :lol:

04-05 50 K miles / 48 months

06+ 36K miles / 36 months

'06 still has the 50k/48 month warranty. They shortened it to 36/36 in '07.

But all 8s have the 60 k /60 month powertrain warranty, and the 8 year internal engine part warranty.

So the shorter bumper-to-bumper (which I believe applies to all Mazdas) has nothing to do with oil specifications for the 8. It's probably to cut their losses on sunvisors, squeaky brakes, etc.

Ken

So does the '04 AT come only with one oil cooler? Should I do to the dealer to have a 2nd one added on or should I just go to outside shop to do it.

As for my compression problems, is it due to carbon build up? What is the cheapest but most effective product to use to clean it? Is there something I can just ass to my gas or do I need to take it fora tune up to get it cleaned.

Lastly if I do use W50 of W60 will this really affect my MPG a lot or is it not noticeable since I'm already getting bad mileage anyways.

'04 AT has one cooler. If you want to add another, going to a dealer or an independent shop or doing it yourself is just a matter of cost and who you think will do it right.

If there's carbon buildup, this is Mazda's method for cleaning it out:

http://www.finishlineperformance.com/pdf/rx8/bulletin/01-014-08-1924f.pdf

There are posts on this site about doing something similar with other products. Search for "sea foam" or variations of "de-carbonize" for those posts.

Personally, I would not use a w50 or w60 oil. 5w20 may be too thin, but 50 or 60 is a huge jump from what Mazda recommends.

Ken

Ken,

Thanks for the info. I will be sure to search this site. For the Oil cooler since it only came with one where would be the place the mount the 2nd one and do you know how much it will cost me to have it done outside.

The second would mount on the other side, the way the MTs come. I've got an MT, so I had two from the start. No idea about the cost...hopefully someone who knows will pipe up.

Ken

Huey52 - take a gallon of water and microwave it for 1 minute. Do the same for a tablespoon of water. The thermal energy input is similar. Which one gets hotter?

Ken,

Thanks for the info. I will be sure to search this site. For the Oil cooler since it only came with one where would be the place the mount the 2nd one and do you know how much it will cost me to have it done outside.

I think the "kit" will cost about 700 something USD. If you buy it within the US

its pretty much plug and play. you can do it yourself if you know where to look for.

I have been using 5w20 per the manual for the first 24,000. I am now considering switching to 5w30 after reading these threads. My only concern is a dealer trying to get out of a warranty claim if I didn't use the "recommended" oil. Has anybody heard of this happening?

I have been using 5w20 per the manual for the first 24,000. I am now considering switching to 5w30 after reading these threads. My only concern is a dealer trying to get out of a warranty claim if I didn't use the "recommended" oil. Has anybody heard of this happening?

remember, recommended is NOT the same as required.

if its REQUIRED, then you might have a problem

but its just RECOMMENDED oil weight, so you can use something else other than 5w20.

Heavier oil can keep the metal to metal contact to a minimum.

I personally use 10w40.

Actually, there's no thermal energy imparted by the microwave (RF) energy itself, but rather by the excitation of the water atoms/molecules themselves, but I see where you're [trying to] go here. ;)

I've been discussing the relatively low thermal mass of our rotary engine, compared to a similarly HP-rated piston engine, and its effect on fuel efficiency. Volumetric vs. thermodynamic efficiency. A different can of worms.

Huey52 - take a gallon of water and microwave it for 1 minute. Do the same for a tablespoon of water. The thermal energy input is similar. Which one gets hotter?

I have been using 5w20 per the manual for the first 24,000. I am now considering switching to 5w30 after reading these threads. My only concern is a dealer trying to get out of a warranty claim if I didn't use the "recommended" oil. Has anybody heard of this happening?

soif you have a warranty claim are you going to blurt out that you used an oil they didn't recommend ?

soif you have a warranty claim are you going to blurt out that you used an oil they didn't recommend ?

Absolutely not, but if they ask to see receipts for oil changes and they look up the UPC codes on the receipts to verify the correct oil was used they could theoretically tell. Maybe I'm just over-thinking the whole issue and being paranoid due to bad experiences with the dealer in the past.

Absolutely not, but if they ask to see receipts for oil changes and they look up the UPC codes on the receipts to verify the correct oil was used they could theoretically tell. Maybe I'm just over-thinking the whole issue and being paranoid due to bad experiences with the dealer in the past.

Unless they can proof the cause of failure was the oil weight itself. (which is impossible)

Actually, there's no thermal energy imparted by the microwave (RF) energy itself, but rather by the excitation of the water atoms/molecules themselves, but I see where you're [trying to] go here. ;)

I've been discussing the relatively low thermal mass of our rotary engine, compared to a similarly HP-rated piston engine, and its effect on fuel efficiency. Volumetric vs. thermodynamic efficiency. A different can of worms.
Fair enough - correction: For similar RF energy inputs into two bodies, similar levels of thermal energy will be induced in both, and the smaller of the two will get hotter.

Our engines are less efficient than the piston variety because rotaries have a larger surface to volume ratio in the combustion chamber. The burn in a rotary quenches over a relatively larger area as it reaches the wall. To get a given amount of energy at the flywheel, you need to burn a given amount of gas. To burn the same amount of gas in both engines, you need to introduce more in a rotary because less of it is burned.

For the same amount of gas burned, you get similar amounts of heat lost to the engine mass. Since the rotary has a lower mass, it tends to get hotter. I assume we have oil coolers for that reason.

This is how I see it. It would be interesting to hear your reasoning as to why the lower 'thermal mass' of a rotary causes it to run cooler.

Sorry, don't have the time to render an epistle on internal combustion engine thermodynamic (vs. volumetric) efficiency, but again there is plenty of substantiating data out there. The unfortunate truth is that despite the wonders of high power output for its mass, our rotaries get poorer gas mileage. But I gladly (well, kinda gladly) pay that concession for all the fun handling the RX-8 provides.

Fair enough - correction: For similar RF energy inputs into two bodies, similar levels of thermal energy will be induced in both, and the smaller of the two will get hotter.

Our engines are less efficient than the piston variety because rotaries have a larger surface to volume ratio in the combustion chamber. The burn in a rotary quenches over a relatively larger area as it reaches the wall. To get a given amount of energy at the flywheel, you need to burn a given amount of gas. To burn the same amount of gas in both engines, you need to introduce more in a rotary because less of it is burned.

For the same amount of gas burned, you get similar amounts of heat lost to the engine mass. Since the rotary has a lower mass, it tends to get hotter. I assume we have oil coolers for that reason.

This is how I see it. It would be interesting to hear your reasoning as to why the lower 'thermal mass' of a rotary causes it to run cooler.

what are your guys thoughts on using a heavier weight like 10W40 or 20W50 as the pervious rotaries have used? i've used the mfr's specified 20W50 all summer long for 10 years in my RX-7's without a problem.does the renesis have THAT much tighter internal tolerances requiring a thinner oil or are they wanting to use 5W20 for fuel mileage and cold start aiding?

5w30 ftw