5w20 vs 5w30
#26
Use 5w-20
USA: 5w-20
HOT CLIMATES: 5w-30 (74°F +)
Why?
If the oil grade is too thick it won't lubricate the contact between the APPEX seal and rotor housing.
Misconception: there's a misconception going around that thicker oil = more protection. This is FALSE. Stop putting heavy V6 & V8(XW-40+) oil on a freaking 1.3L tighlty compact engine. Trust me I followed this fad and that's how my first RX8 went to ****.
By the way: if you use THICK grade oil it will wear out your seals faster on COLD-STARTUPS. Trust me just use 5w-20 and pre-mix if your going to rip it in the Northeast states. It's how I maintain my RX8 as a daily driver and it fixed a bunch of my problems.
Tips: 5w-30 is a big difference from 5w-20 on rotary engines. We're talking really tightly compact engines. If the oil is too thick it's flow rate may be slower.
If your car is smoking blue on cold startups for a really long time MY POINT EXACTLY
EDIT: If your claim is to use heavier oil as a method to maintain cool temperature on the engine. You suck.. Get a better radiator, better oil coolers or an early fan trigger. If you go with a cheap option such as just using thicker oil you are going to get CHEAP results.
ALSO ALSO: I noticed from running several test that thicker grade oil has raised the engine load % on my engine.
HOT CLIMATES: 5w-30 (74°F +)
Why?
If the oil grade is too thick it won't lubricate the contact between the APPEX seal and rotor housing.
Misconception: there's a misconception going around that thicker oil = more protection. This is FALSE. Stop putting heavy V6 & V8(XW-40+) oil on a freaking 1.3L tighlty compact engine. Trust me I followed this fad and that's how my first RX8 went to ****.
By the way: if you use THICK grade oil it will wear out your seals faster on COLD-STARTUPS. Trust me just use 5w-20 and pre-mix if your going to rip it in the Northeast states. It's how I maintain my RX8 as a daily driver and it fixed a bunch of my problems.
Tips: 5w-30 is a big difference from 5w-20 on rotary engines. We're talking really tightly compact engines. If the oil is too thick it's flow rate may be slower.
If your car is smoking blue on cold startups for a really long time MY POINT EXACTLY
EDIT: If your claim is to use heavier oil as a method to maintain cool temperature on the engine. You suck.. Get a better radiator, better oil coolers or an early fan trigger. If you go with a cheap option such as just using thicker oil you are going to get CHEAP results.
ALSO ALSO: I noticed from running several test that thicker grade oil has raised the engine load % on my engine.
Last edited by Eros Nunez; 01-10-2019 at 12:56 PM.
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Kevinboomkens (07-08-2021)
#28
5w-30 is perfectly healthy for summer drives but it will wear out your engine in the winter (40° and below)
My personal recommendation is:
Track: 5w-30(temps must be 65°F+)
Winter/spring: 5w-20 + pre-mix if your ripping it.
Anything heavier than 5w-30 will cause friction between the seals. You must remember the space between the housing and the seals is VERY small. Thicker grade oil will just get dragged by the seals and not flow in between the seals and the housing. Which is what we want.
#29
Smoking turbo yay
Aside from reviving an 11-year-old thread...
I do agree that 5W-20 is adequate for cooler climates. This is what I use for spirited DD and occasional AutoX.
But some people have used XW-40 without issues, and in fact, I would use it if my car sees track time. You need that thicker oil for tracking where your RPM, load and temperature will be so high the thinner 20 oil will break down.
See the UOA thread if you want data.
I do agree that 5W-20 is adequate for cooler climates. This is what I use for spirited DD and occasional AutoX.
But some people have used XW-40 without issues, and in fact, I would use it if my car sees track time. You need that thicker oil for tracking where your RPM, load and temperature will be so high the thinner 20 oil will break down.
See the UOA thread if you want data.
#30
Registered
I’ve been using pennzoil yellow bottle @ 10w40 as per the recommendation of several Rotary engine builders. I’m in FL so weather is typically near HELL conditions but right now it does dip into the 30s-40sF in the AM startup. I wanted to switch to something thinner for winter temps but honestly... the pour point of the 10w40 is freakin -38F!!!! As per the data sheet. I don’t think flow is an issue @ 40F in the morning. Lol.
I run the car HARD daily as soon as it warms up.
I run the car HARD daily as soon as it warms up.
#31
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I’ve been using pennzoil yellow bottle @ 10w40 as per the recommendation of several Rotary engine builders. I’m in FL so weather is typically near HELL conditions but right now it does dip into the 30s-40sF in the AM startup. I wanted to switch to something thinner for winter temps but honestly... the pour point of the 10w40 is freakin -38F!!!! As per the data sheet. I don’t think flow is an issue @ 40F in the morning. Lol.
I run the car HARD daily as soon as it warms up.
I run the car HARD daily as soon as it warms up.
sorry pics are so BIG!
#32
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Heck, in Florida you could probably go with 20w-40 or 20w-50.
I disagree with your engine builder that you should let it warm up for 5-10 minutes before driving it. The period from cold start to warm up is when a large amount of carbon is produced. Doing things to minimize this time (i.e. driving while keeping the RPM's under 4-5k) is a good plan.
I disagree with your engine builder that you should let it warm up for 5-10 minutes before driving it. The period from cold start to warm up is when a large amount of carbon is produced. Doing things to minimize this time (i.e. driving while keeping the RPM's under 4-5k) is a good plan.
#34
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#37
Water Foul
Are we rehashing the oil wars again? Mobil 1 0W40 for me, changed every 3K miles, with a filter change every 6K miles.
Sure, but don't you have something like 5 miles on your car?
.
.
Last edited by Steve Dallas; 04-23-2019 at 08:07 PM.
#38
Smoking turbo yay
I currently have 60+k and I am sure my car has only ever seen 5W-20. Works fine. I don't track or live in a hot climate, though.
#39
Yeah, something like 5 miles. Lemme check... oh, 47.5K miles. You’re only off by 46,995 miles. But hey, why let facts get in the way of a long-standing false rx8club.com narrative, right?
Last edited by New Yorker; 04-22-2019 at 06:44 PM.
#40
Water Foul
Yeah, something like 5 miles. Lemme check... oh, 47.5K miles. You’re only off by 46,995 miles. But hey, why let facts get in the way of a long-standing false rx8club.com narrative, right?
I'm not a hater; I love my 8. But, I do deal in facts, and many people would expect a 14 year-old car to have ~160K miles on it. Forty-eight thousand is much lower than average for a car of that age, and I find it a bit disingenuous to report only the car's age.
.
Last edited by Steve Dallas; 04-22-2019 at 08:06 PM.
#41
Got it.
#42
Smoking turbo yay
So, in other words, 14+ years ownership without a single engine problem doesn’t really count if there are only 47.5K miles on the car. 14+ years ownership with no engine problems is only meaningful if said car has 160K miles on it. Or, put another way, 47.5K miles with not one engine problem ain’t news for the Renesis if I took my time racking up that mileage. Because... because... having many days off between rides gave my car time to magically heal itself of any developing compression issues! Instead of my seals wearing down like so many Renesis seals allegedly do (well, the ones we read about on internet forums, anyway), mine, sitting quietly in a dark garage for four, five, six, maybe ten days between rides, had a secret advantage! They could magically restore... yeah, that’s it, restore themselves back to spec, not unlike the way Christine could heal and renew herself overnight in what I used to think was a fictional movie!!!
Got it.
Got it.
There are parts that are more related to age, like a bunch of plastic parts(although more heat cycles still would break them faster) and brake fluid, but engine wear is definitely mileage related. The less you drive it, the less wear there will be. There are zero problems I see with that logic.
No one said your car will magically heal itself. The point is that your car will very likely have less wear than Steve's or my car because we have more mileage.
And there is a reason oil threads always go to ****. Just realize each person's use case is different so one choice that works for one person won't work for another. As long as you have a valid argument behind your reasoning, keep doing what you are doing, and just agree to disagree with others.
#44
Registered
Mine is coming up on 130k miles. I bought the car with around 70k miles, still original engine. Only ever used 5w-20.
I try to keep oil change frequency to around every 7,000 miles.
I'm debating whether to even pursue the Sohn modification at this point.
I try to keep oil change frequency to around every 7,000 miles.
I'm debating whether to even pursue the Sohn modification at this point.
#45
Registered
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So, in other words, 14+ years ownership without a single engine problem doesn’t really count if there are only 47.5K miles on the car. 14+ years ownership with no engine problems is only meaningful if said car has 160K miles on it. Or, put another way, 47.5K miles with not one engine problem ain’t news for the Renesis if I took my time racking up that mileage. Because... because... having many days off between rides gave my car time to magically heal itself of any developing compression issues! Instead of my seals wearing down like so many Renesis seals allegedly do (well, the ones we read about on internet forums, anyway), mine, sitting quietly in a dark garage for four, five, six, maybe ten days between rides, had a secret advantage! They could magically restore... yeah, that’s it, restore themselves back to spec, not unlike the way Christine could heal and renew herself overnight in what I used to think was a fictional movie!!!
Got it.
Got it.
If you don't drive the car, the seals don't deteriorate. So the only thing that matters is mileage, of which you have an unremarkable amount to claim some superiority over other owners whose engines have failed, or over the notion that engines fail.
#46
Smoking turbo yay
And speaking of seals... I think oil won't make as much of a difference once sprayed into the combustion chamber. The bearings will be more sensitive to the viscosity of the oil.
#47
Registered
sweet mother of pearl... and here I am doing quick drain n fills every 1,500 miles (leaving the oil filter alone for several more oil changes) with 10w40 to insure adequate viscosity at all times. Hmmmmm.
#49
I don't get it, are you arguing against your own point?
If you don't drive the car, the seals don't deteriorate. So the only thing that matters is mileage, of which you have an unremarkable amount to claim some superiority over other owners whose engines have failed, or over the notion that engines fail.
If you don't drive the car, the seals don't deteriorate. So the only thing that matters is mileage, of which you have an unremarkable amount to claim some superiority over other owners whose engines have failed, or over the notion that engines fail.
Got it.
#50
The Blue Blur
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