Cold weather use K20A3 oil choice

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K20A3 engine with 100k miles

So I have an Acura Rsx Type S which is my wife's winter beater (pretty fun winter beater if you ask me). I change oil every 6 months whether it gets used or not. I am probably throwing away oil but it is what it is.

95% of it's use is in Chicago winter through stop and go traffic commuting 5 days a week. Other than that it just sits.

It rev hangs for a looooonnnnnggg time when you start it when it's any sort of cold outside. I have notice this is temperature related.

I have been using PUP 5W30 but want to throw in a 0W so I don't have wait forever for it to heat up.

Only options I really see are M1 0w30 and M1 0w40. Wondering if I should go the 0w40 because of engine age or stick to 0w30 since it's cold weather use only.

Also open to any other suggestions and will easily change my mind when logical data is presented.
 
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If you have RSX Type-S, it's not K20A3, but it's A2.

You don't have to wait forever to heat it up, that engine is bulletproof and will serve you well if you keep OCIs reasonable. Just wait a few seconds and start driving, don't go over 3000 rpm for the first 15 minutes and you'll be fine.

If you wait forever to heat it up, actually that's more harmful. You not only waste fuel but it's hard on motor oil. Fuel contamination is the last thing you would want, which means your oil will thin out quicker, no Bueno for a high-revving engine.

I'd start with 0w30 if it's a beater and only for commuting. 0w40 would be a better application for spirited driving/track/autox etc. If it doesn't burn too much oil, you're good to go. 0w oil works just fine, I tried pretty much everything in that engine, all types of oil and all types of mods (turbo/supercharger and naturally aspirated)

I'd be worried about transmission fluid as well, synchros are the weakest link of the whole drivetrain, so you need to change MTF regularly. I'd recommend changing it every 3 oil changes, as your OCIs are pretty short.

If you are at 100k, it's time for a spark plug change and valve adjustment. It literally takes less than 2 hours to get it done yourself. Also, check vtec selenoid gaskets, etc. Also change the coolant if you haven't done yet.
 
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You won't notice the difference between 0w and 5w in the cold so it's your choice. Your idle is hanging because that's what the computer is doing. The wife's Toyota does the same.

If it's a beater I would be running SuperTech Synthetic if your WalMart carries the cheap stuff.

And yes, with that type of driving every six months is a good plan.
 
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Oil viscosity is going to have a negligible effect on how quickly your car warms up. You'd see an actual benefit from installing a block heater, or even insulating your oil filter.

Viscosity more determines the pumpability and flow characteristics, it doesn't determine thermal retention factors.
 
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Oil viscosity is going to have a negligible effect on how quickly your car warms up. You'd see an actual benefit from installing a block heater, or even insulating your oil filter.

Viscosity more determines the pumpability and flow characteristics, it doesn't determine thermal retention factors.

Technically he is right, it takes less time to get to the operating temperature, but the difference is negligible.
 
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Thicker oil heats up faster than thinner oil but no one will ever see a difference between a 30 and a 40-grade.

As long as you are starting above -30 or so then the difference between a 5W winter rating and an oil with a 0W rating is both unknown and immaterial. Below that use an oil with a 0W rating. The 0W oils are not “cold use only”, where did you get that idea?

If fuel dilution is an issue then always use the higher grade. You can’t combat it any other way besides a short OCI.
 

Bmsluite

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If you have RSX Type-S, it's not K20A3, but it's A2.

You don't have to wait forever to heat it up, that engine is bulletproof and will serve you well if you keep OCIs reasonable. Just wait a few seconds and start driving, don't go over 3000 rpm for the first 15 minutes and you'll be fine.

If you wait forever to heat it up, actually that's more harmful. You not only waste fuel but it's hard on motor oil. Fuel contamination is the last thing you would want, which means your oil will thin out quicker, no Bueno for a high-revving engine.

I'd start with 0w30 if it's a beater and only for commuting. 0w40 would be a better application for spirited driving/track/autox etc. If it doesn't burn too much oil, you're good to go. 0w oil works just fine, I tried pretty much everything in that engine, all types of oil and all types of mods (turbo/supercharger and naturally aspirated)

I'd be worried about transmission fluid as well, synchros are the weakest link of the whole drivetrain, so you need to change MTF regularly. I'd recommend changing it every 3 oil changes, as your OCIs are pretty short.

If you are at 100k, it's time for a spark plug change and valve adjustment. It literally takes less than 2 hours to get it done yourself. Also, check vtec selenoid gaskets, etc. Also change the coolant if you haven't done yet.
What is the valve adjustment? I did the plugs, coils, coolant, trans fluid, valve cover gasket, new vtec solenoid 5k ago.

Also, I hear it rattle everytime it starts up. I was told multiple times by multiple people that that is normal timing chain Tensioner noise for this engine. True?

I will go 0w30 then. I run it to redline a bunch of times when I drive it but she never does. The car is slow but when that vtec hits its really fun for some reason lol
 

Bmsluite

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Oil viscosity is going to have a negligible effect on how quickly your car warms up. You'd see an actual benefit from installing a block heater, or even insulating your oil filter.

Viscosity more determines the pumpability and flow characteristics, it doesn't determine thermal retention factors.
Insulated oil filter? How much of a difference would this make when the startups are 8 and 11 hours apart respectively
 

Bmsluite

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You won't notice the difference between 0w and 5w in the cold so it's your choice. Your idle is hanging because that's what the computer is doing. The wife's Toyota does the same.

If it's a beater I would be running SuperTech Synthetic if your WalMart carries the cheap stuff.

And yes, with that type of driving every six months is a good plan.
Gotcha. Yeah it just seemed odd that it hangs for so long on these cars.
 
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What is the valve adjustment? I did the plugs, coils, coolant, trans fluid, valve cover gasket, new vtec solenoid 5k ago.

Also, I hear it rattle everytime it starts up. I was told multiple times by multiple people that that is normal timing chain Tensioner noise for this engine. True?

I will go 0w30 then. I run it to redline a bunch of times when I drive it but she never does. The car is slow but when that vtec hits its really fun for some reason lol

If it rattles when you start it up, it's most likely coming from the VTC actuator, it's also an easy (but more time-consuming) job that can be done at the same time with the valve adjustment. Common problem for these engines. My CR-V's K24 engine also rattles occasionally.

Valve adjustment can be found anywhere, just search your engine code and valve adjustment and you'll find tons of videos/articles about it.l
 
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Bmsluite

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Is the thermostat working properly? You’re looking at the oil which would have relatively little impact especially within the confines of the winter rating.
OH yeah, it heats up faster than any vehicle I have ever owned. Well, my track car might heat up a bit quicker but that's another animal entirely
 

Bmsluite

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If it rattles when you start it up, it's most likely coming from the VTC actuator, it's also an easy (but more time-consuming) job that can be done at the same time with the valve adjustment. Common problem for these engines. My CR-V's K24 engine also rattles occasionally.

Valve adjustment can be found anywhere, just search your engine code and valve adjustment and you'll find tons of videos/articles about it.l
Gotcha. OK, I'll add that to the list of things to do to that car. Is anything catastrophic going to happen if I wait until spring to do that? Getting cold and my hands have bad circulation
 
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Insulated oil filter? How much of a difference would this make when the startups are 8 and 11 hours apart respectively
Minimal, when your ambient temperature is below freezing for that long with a small displacement aluminum block and head. My iron block 4.6L will cool from operating temp to ambient temp in 2 hours or less in those conditions.
 

Bmsluite

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If it rattles when you start it up, it's most likely coming from the VTC actuator, it's also an easy (but more time-consuming) job that can be done at the same time with the valve adjustment. Common problem for these engines. My CR-V's K24 engine also rattles occasionally.

Valve adjustment can be found anywhere, just search your engine code and valve adjustment and you'll find tons of videos/articles about it.l
Do you mean the VTEC sprocket thing is causing the noise? This thing?
 

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A long time for the revs to drop. Not to heat up. Thought maybe the revs hung for so long because it was trying to pump oil around
Uhh no. The engine management system keeps the idle speed higher to warm the engine so the emission control system can operate. If your engine speed is remaining elevated then the engine is either not warming up or it doesn’t think that it is. It will also inhibit the shift points of the transmission for the same reason.
 
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