synthetic to conventional, biannual rotation

[k24a4]

I'm considering switching to conventional PYB for the Summer (May through November) and Synthetic for the Winter (Nov-April) here in Boston. I'm not concerned with wear or the cleaning abilities of the oils, since the OCI will fall comfortably in the 5-7.5k range. My question is whether switching back and forth on a yearly basis will affect any of the engine seals. I can't seem to find a consensus on this issue by searching.

The car in question is 2004 4cyl Honda Accord seeing about a 60/40 split city to highway miles annually. The car has never seen straight conventional oil, save for the factory fill, changed at 4200 miles. The next 40,000 saw Kendall GT1 semi-syn at 5k oci and the last 40,000 PP at 5k OCI.

The Wintertime synthetic use would be for cold start peace of mind.

 

[dtt004]

Hi.

No it won't hurt your engine seals.

 

[Quattro Pete]

I think that will be fine, but if it was me, I'd probably do one of two things:

A) Find a middle ground and run a synthetic blend (such as Motorcraft 5w-20) all year long at 5-7K miles

or

B) Find a synthetic that can go 10-12K miles and just run that all year long.

I'm assuming you're doing it for cost reasons.

 

[sciphi]

Switch away. My Buick's switched back and forth many times. There's no leaking from the seals.

I'm going to do the same thing this summer with PYB and QSUD for the winter. IIRC the PYB is SN flavor and the QSUD is SM, both in 5w-30.

 

[simple_gifts]

OT: That is semi-annual, not biannual.

edit;it appears they are synonymous; biannual apparently means twice a year or every two years; crazy...

 

[moto94536]

been running castrol syntec for couple years. I am switching to chevron supreme soon.. the reason I am doing it cost reasons, and want to try the chevron SN gf5.

 

[Artem]

I don't see why you don't just run the same oil all year long. Why switch back and forth?

 

[Quattro Pete]

Originally Posted By: simple_gifts

edit;it appears they are synonymous; biannual apparently means twice a year or every two years; crazy...


biannual - occurring twice a year
biennial - occurring every two years

 

[k24a4]

Originally Posted By: dtt004
Hi.

No it won't hurt your engine seals.


Thanks. I was hoping someone with a technical backround would chime in.

 

[k24a4]

Originally Posted By: Quattro Pete
I think that will be fine, but if it was me, I'd probably do one of two things:

A) Find a middle ground and run a synthetic blend (such as Motorcraft 5w-20) all year long at 5-7K miles

or

B) Find a synthetic that can go 10-12K miles and just run that all year long.

I'm assuming you're doing it for cost reasons.


Good advice. I have a jug of Motorcraft semi-syn in my stash. I'll see how the Accord likes it, if not this coming OCI, the next one.

 

[Oregoonian]

Originally Posted By: Quattro Pete
I think that will be fine, but if it was me, I'd probably do one of two things:

A) Find a middle ground and run a synthetic blend (such as Motorcraft 5w-20) all year long at 5-7K miles

or

B) Find a synthetic that can go 10-12K miles and just run that all year long.

I'm assuming you're doing it for cost reasons.

+1....for option B...

IMO.....using a long OCI oil makes sense....especially if you doing 10-12K a year.

Suggest M1 5w20EP....guaranteed for 15K (but I would only do 10-12K).....and a good high-tier filter such as an M-1EP. One oil cange a year....make up for the slight additional cost of oil and filter.
_______________________________________
03' Ford Focus (2.3L Duratec PZEV)/ 95K
M-1 5w20EP / OCI: 1 year or 10,000 +/-
Filter: M1 102EP

 

[The Critic]

Originally Posted By: dtt004
Hi.

No it won't hurt your engine seals.

Then why does Toyota recommend that once you switch to synthetic, you must stay with it?

 

[mechtech2]

critic -
Why do shampoos say on the bottle, "Lather, rinse, repeat"?

 

[Greggy_D]

I do the same. I run syn from Dec-Apr and dino the rest of the year.

 

[Quattro Pete]

Originally Posted By: The Critic
Then why does Toyota recommend that once you switch to synthetic, you must stay with it?

We should probably ask Toyota. I'm curious to hear their explanation, confirmed by scientific studies that back this up.

 

[johnachak]

I think that will be fine, but if it was me, I'd probably do one of two things:

A) Find a middle ground and run a synthetic blend (such as Motorcraft 5w-20) all year long ...

Granted Im talking about a Ford but I use the MC 5w 20 blend in the warm weather and synthetic (usually motorcraft, kendall or pp -I know, strange combo. In the winter for cold weather starts. Only around 40,000 mi but she seems to lolike the system. Eliminated the cold startup noises...

 

[tig1]

And the reason for doing this is????

 

[yaris0128]

Im sure in your area you could run dino year round. Syntheic isnt that much better for cold flow as a lot of us think. It has to be super freaking cold. It is totally fine if you switch back and forth. I do that quite a bit. Sometimes I just dont feel like spending the money.

 

[johnachak]

Originally Posted By: tig1
And the reason for doing this is????


I dont usually have time to warm up the car in the winter. I put her in gear and take it easy. Until i went with syn in the winter she made noises when i hit the gas for a few minutes (not a pleasant sound either). With the syn it doesnt. Three winters now and shes fine taking off ice cold. The first two werent so nice...
Since the only difference is the full syn, i have to believe that is the difference.

 

[yaris0128]

^
In that case since it works better for you period why not just stick with a syn all year.