Coolant Change Interval for Infrequently Driven Car (Hyundai Genesis Coupe)

[nobb]

The OEM recommendation for my Hyundai Genesis Coupe is to change the coolant initially at 5 years (100,000 kms), then every 2 years (50,000 kms). However, I only drive this vehicle in the summer so in a year I might only put 5000 kms on it. Would the time based interval still apply? Does coolant degrade with time AND mileage?

Strangely, the OEM coolant was blue but the genuine Hyundai coolant I bought from the dealership (concentrated) was green. I wonder if the OEM coolant is some sort of super long life formulation while the dealership stock is standard old school stuff? Ideally I would love to use some sort of long life coolant that I can safety go for extended periods of not changing. Most new vehicles seem to have coolant change intervals of 5 years or more so every 2 years seems kind of excessive.

 

[ZeeOSix]

The factory "super long life" coolant (pink colored) in my Tacoma was a 10 year or 100,000 mile initial change interval. I had orange Dex-Cool (rated as a 5 year/150K mile coolant) in a motorcycle for 10 years, and the inside of the radiator looked like new which surprised me. The bike didn't get ridden much, so maybe just sitting does help the coolant last longer than if the vehicle is used all the time. I'm not going to let it go that long again though just to be safe.

 

[Ed_Flecko]

Here's a couple of great articles that should answer most of your questions.

Take a look at: https://bit.ly/2XqXdly and https://bit.ly/2IMQ3UD

Ed

 

[JHZR2]

Just pulled 10yo OAT coolant out of a 37 yo all original system, and it looked great, clean and clear.

My suspicion is that Genesis reduces the subsequent interval due to an assumption of tap water use. I'm not sure Honda does the same when all they supply is 50/50 premix with controlled water.

My greatest concern is localized depletion of additives in seldom used vehicles. Glycol doesn't really degrade, and oat additives deplete very slowly (slower at lower temperatures unless stray currents are present), but if in smaller passages they do deplete due to the local environment, I'd be concerned that lower local concentrations of inhibitors could be an issue.

But ai have no data to back up that it's amconcern, at least given the low depletion of OATs.

 

[CT8]

The OEM recommendation for my Hyundai Genesis Coupe is to change the coolant initially at 5 years (100,000 kms), then every 2 years (50,000 kms)

 

[nobb]

Originally Posted by Ed_Flecko
Here's a couple of great articles that should answer most of your questions.

Take a look at: https://bit.ly/2XqXdly and https://bit.ly/2IMQ3UD

Ed


Thanks, that was a very good read but they seemed to be giving very generic advice for replacement intervals (eg. 5 yrs initial, 3 yrs after).

My ownership experience from various manufacturers has the replacement intervals all over the place with little reasoning:

2011 Hyundai: 5 yrs initial, 2 after
2015 Dodge: 10 yrs
2006/2008 Ford: 6 yrs initial, 3 after
1998 Toyota: 2 yrs

 

[WyrTwister]

Just drop a lower radiator hose every couple of years , re-attach and pour in a gallon of coolant ( the same that is in it ) . Problem solved .

 

[Ponchinizo]

Originally Posted by Ed_Flecko
Here's a couple of great articles that should answer most of your questions.

Take a look at: https://bit.ly/2XqXdly and https://bit.ly/2IMQ3UD

Ed


Mostly stuff I already knew, with a few things I didn't! Thanks for that link Ed, great read. Always glad to review the more basic stuff to make sure I've got it right.

 

[dubber09]

Originally Posted by WyrTwister
Just drop a lower radiator hose every couple of years , re-attach and pour in a gallon of coolant ( the same that is in it ) . Problem solved .


That's what I do except I drain using drain valve/ pepcock.

 

[nobb]

Originally Posted by dubber09
Originally Posted by WyrTwister
Just drop a lower radiator hose every couple of years , re-attach and pour in a gallon of coolant ( the same that is in it ) . Problem solved .


That's what I do except I drain using drain valve/ pepcock.


I find the petcock too slow. Also the higher velocity from just dumping a big volume with the hose method helps flush out stuff that has accumulated at the bottom.

 

[Lubener]

I have two 87's which I change the old green stuff w/ distlled water every 5 years, not by mileage. It comes out clear. I still have the original radiators in use.

 

[Mad_Hatter]

Originally Posted by CT8
The OEM recommendation for my Hyundai Genesis Coupe is to change the coolant initially at 5 years (100,000 kms), then every 2 years (50,000 kms)


Follow the mfgs spec, period. The mfg spent a lot of time and money testing components and they know what works best. For example, do you know what grade of aluminum is in your radiator and engine block? Not all aluminum is created equal, some grades have better corrosion resistance properties than others. Plus over time your coolant will have lesser ability to keep the pH balanced and prevent seals from going bad. If your pH gets to low it's going to start pitting the aluminum.

A healthy cooling system is essential, this is not one area I would try and save a few bucks on... follow the mfgs recommendation.