HM Syn Oil Recommendation.

[Ant57]

Bought a '99 Accord 2.3 in good shape, 114 k miles. I'm going to use a HM Syn Oil. Do any brand(s) stand out for a 25 year old engine? How do the additive formulas differ?

Thanks

Adam

 

[kschachn]

Bought a '99 Accord 2.3 in good shape, 114 k miles. I'm going to use a HM Syn Oil. Do any brand(s) stand out for a 25 year old engine? How do the additive formulas differ?

Thanks

Adam

Who knows what the "additive formulas" are? How would we know?

 

[JavierH19]

HM oil just have more seal conditioners than non hm oils. Seal conditioners can sometimes reduce leaks or prevent leaks from happening for longer. Some believe that hm oils will also be at the thicker side of whatever viscosity grade they are in but looking at data sheets I've seen the hm version's be thinner sometimes. For the most part they're similar from one brand to another. If it was mine I'd probably just use supertech 5/10w-30 HM. I don't know if they have 10w-40 in HM anymore but that would also be an option. If it doesn't leak I'd see myself using 15w-40 as well.

 

[Oily Ed]

I’d suggest the Quaker State synthetic high mileage 5w30. You can find a voa with a search. Its also Dexos1 Gen3 approved

 

[daves87rs]

Any HM oil will do. Accords of that era nearly run on anything…….

 

[Bill7]

Who knows what the "additive formulas" are? How would we know?

The high

HM oil just have more seal conditioners than non hm oils. Seal conditioners can sometimes reduce leaks or prevent leaks from happening for longer. Some believe that hm oils will also be at the thicker side of whatever viscosity grade they are in but looking at data sheets I've seen the hm version's be thinner sometimes. For the most part they're similar from one brand to another. If it was mine I'd probably just use supertech 5/10w-30 HM. I don't know if they have 10w-40 in HM anymore but that would also be an option. If it doesn't leak I'd see myself using 15w-40 as well.

I've also noticed that High Mileage Full Synthetic oils tend to have more phosphorous and zinc (anti-wear) additives and more calcium (detergent) additives than their non high mileage full synthetic couterparts of the same brand.

 

[Donald]

HM oils have two properties typically. An additive to swell seals and stop leaks. Thicker in their weight class.

Except for rear main I would repair any other gasket or seal that was leaking.

Unless it's burning oil I don't see a need for thicker oil.

It's a 25 year old vehicle. I would not get carried away on the oil.

 

[JeffKeryk]

I used to use a lot of the Valvoline Syn. On your Accord, anything will work. The Costco Kirkland 5w30 is an economic choice that offers a lot of value. I keep QS Syn on the shelf as well.

 

[tnt_motorsports]

@Ant57
FWIW, for the cost it's difficult to beat Super Tech FS HM IMO.

I've had good luck with Mobil 1 & Citgo as well...

Just my $0.02

 

[burbguy82]

I have had great results with Valvoline Maxlife in the past. Maybe I am lucky. One instance of a stuck ring=unstuck, and one instance of a seal leak=stopped the leak, for a while at least.

This is with the "synthetic blend".

 

[meep]

HM oils have two properties typically. An additive to swell seals and stop leaks. Thicker in their weight class.

Except for rear main I would repair any other gasket or seal that was leaking.

Unless it's burning oil I don't see a need for thicker oil.

It's a 25 year old vehicle. I would not get carried away on the oil.

Agree with this. All of it. Including the don’t use it unless you see some burning or leaking.