Using conventional 10w30 in the summer and 5w30 synthetic in the winter

[Dru2u]

(Skip to the second paragraph to get to the background of my question, and the third for my question)

Hey folks, this is my first post. Realize as I write this I'm hesitant to write it, because I can already hear the obvious objections, but I gotta throw something on the wall and get my name up there. In part to first say thanks for the site and forums, BITOG. I've been searching the web, and stumbling across articles on here for at least a year, and it has really helped me to understand significantly better. Specifically, I'd like to mention there was a really good article, perhaps written in a forum thread style, and maybe truly as a forum thread, that put to rest the reliance on K100 spec as the operating viscosity and how the HTHS 200 and viscosity index are better data to consider. I will have to find that link again and read it again already as I'm starting to forget the terms as you can see. It will be bookmarked and used as a reference in the future. To my question however...

I have a 2008 Grand Prix with the GM 3800 series/mark III motor. Currently it has 180k miles, and I've run synthetic in it since I got it with 12k miles. I live in northern Missouri. I drive a work vehicle daily, so this car sits until the weekends when I make an self-imposed obligatory trip just to get it out and warm it up, and keep it from developing flat spots on the tires. I absolutely will not short trip it when I do get it out. I will either skip a weekend or, (cringe) two weekends, but I will not drive it less than 50+ miles one-way to go somewhere and then return in the evening.

I have to admit that I am a meddler. I love fixing things that are not broken. Why I even ask on here is because I like seeing what others have to say, and perhaps will suggest something I have not already thought of. My question is what will happen if I use 10w30 conventional oil with SN and SN plus GF6A ratings, lacking Dexos, May 1 to September 30, before switching back to the recommend 5w30 spec specified in the manual, synthetic, and with Dexos rating?

Summer Plan (5-months; May thru September): Conventional 10w30 GF6A SN Plus (perhaps Castrol GTX)
Winter Plan (7-months; October thru April): Synthetic 5w30 GF6A SN Plus Dexos (PDS: https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_SB.pdf)
Alternative Winter Plan: Synthetic 0w30 as not starting more frequently than on the weekends seems to produce dry starts for the first second in sound on that first weekend startup, and perhaps a 0w would really help me out a lot there.

Additional Info: DIC (Dashboard Information Center) says that I've got 60% oil life remaining, current OCI is just over 6k miles, Aug 2023 (9-months +/-). And if someone tells me I could delay my oil change until after I put a big trip on the oil May 9, and drive 2,000 miles in four days, then I'd be willing to delay this until I get back, and then change the oil.

 

[Fa24wrx]

Why conventional? Why not just a thick synthetic?

 

[JavierH19]

I'd suggest you just switch to supertech 5w-30 full syn and use that year round since it's $19. It's cheaper and better than castrol gtx conventional which is $23 and way overpriced for what it's worth. And for the same $23 as that conventional you can get Quaker state euro 5w-40 which is superior to whatever that brand is that I've never heard of. Spend a wee bit more and you can get Mobil or Castrol 0w-40. It's what I'd do if it was mine and lived in a cold area.

 

[Bottom_Feeder]

It's a 16 year old car with 180k miles on it. It really doesn't matter what you put in it at this point.

 

[TomYoung]

There is really no place in the world for conventional oils. You should be running a decent, budget-minded synthetic, like Quaker State, Supertech, Pennzoil etc, in one weight, year-round. I wish you well with that cool car.

 

[dubber09]

Valvoline Daily Protection is a blend, good one too, usually cheap.

 

[goingplacesanddoingstuff]

I’d worry less about the winter rating and more about the quality of the actual oil. Any full synthetic 5w30 or 0w30 would be just fine year round.

If it were me, I’d probably run HPL Premium Plus or Amsoil SS 5w30. Or, if boutique oil isn’t the ticket, perhaps M1 Euro 0w40.

 

[wlk]

You could run 10w30 year round if you want to, I did all my 3.1l gm's in PA. Nothing would be wrong if you wanted to go the 5w W & 10w S, whichever is easiest, those motors are pretty tough.

 

[SC Maintenance]

Your definately overthinking this. There is going to be no functional difference on a 5w-30 or a 10W-30 on the hot end. The small amount of synthetic or VI in a 5W-30 is also not going to do much difference for the hot end on a short OCI. I am running 10W-30 in one of mine now because I got it super cheap - $11 for 6 quarts of Valvoline. Of course it seldom freezes here so thats one factor. When I run out I will go back to 5w-30 unless I find a deal on something.

I would just buy whatever brand you can get cheap or whatever brand you like. Changing to 10W specifically for summer in this case makes little sense to me.

 

[RDY4WAR]

I think all you'll do is make your wallet lighter. Given the use and approximate miles, keep 5W-30 synthetic in and change it once a year.

 

[nicholas]

A good syn is so cheap
Why bother.

 

[cmarshall78]

Where are you finding SN oil at?

 

[BMWTurboDzl]

(Skip to the second paragraph to get to the background of my question, and the third for my question)

Hey folks, this is my first post. Realize as I write this I'm hesitant to write it, because I can already hear the obvious objections, but I gotta throw something on the wall and get my name up there. In part to first say thanks for the site and forums, BITOG. I've been searching the web, and stumbling across articles on here for at least a year, and it has really helped me to understand significantly better. Specifically, I'd like to mention there was a really good article, perhaps written in a forum thread style, and maybe truly as a forum thread, that put to rest the reliance on K100 spec as the operating viscosity and how the HTHS 200 and viscosity index are better data to consider. I will have to find that link again and read it again already as I'm starting to forget the terms as you can see. It will be bookmarked and used as a reference in the future. To my question however...

I have a 2008 Grand Prix with the GM 3800 series/mark III motor. Currently it has 180k miles, and I've run synthetic in it since I got it with 12k miles. I live in northern Missouri. I drive a work vehicle daily, so this car sits until the weekends when I make an self-imposed obligatory trip just to get it out and warm it up, and keep it from developing flat spots on the tires. I absolutely will not short trip it when I do get it out. I will either skip a weekend or, (cringe) two weekends, but I will not drive it less than 50+ miles one-way to go somewhere and then return in the evening.

I have to admit that I am a meddler. I love fixing things that are not broken. Why I even ask on here is because I like seeing what others have to say, and perhaps will suggest something I have not already thought of. My question is what will happen if I use 10w30 conventional oil with SN and SN plus GF6A ratings, lacking Dexos, May 1 to September 30, before switching back to the recommend 5w30 spec specified in the manual, synthetic, and with Dexos rating?

Summer Plan (5-months; May thru September): Conventional 10w30 GF6A SN Plus (perhaps Castrol GTX)
Winter Plan (7-months; October thru April): Synthetic 5w30 GF6A SN Plus Dexos (PDS: https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_SB.pdf)
Alternative Winter Plan: Synthetic 0w30 as not starting more frequently than on the weekends seems to produce dry starts for the first second in sound on that first weekend startup, and perhaps a 0w would really help me out a lot there.

Additional Info: DIC (Dashboard Information Center) says that I've got 60% oil life remaining, current OCI is just over 6k miles, Aug 2023 (9-months +/-). And if someone tells me I could delay my oil change until after I put a big trip on the oil May 9, and drive 2,000 miles in four days, then I'd be willing to delay this until I get back, and then change the oil.

If you're a meddler welcome to the world of meddlers. You'll unlikely find another automotive site with more meddling than BITOG.


Note: It takes months for soft high performance summer tires to flat spot. Tires will not flat spot over a weekend. IJS

 

[Ride_Red]

(Skip to the second paragraph to get to the background of my question, and the third for my question)

Hey folks, this is my first post. Realize as I write this I'm hesitant to write it, because I can already hear the obvious objections, but I gotta throw something on the wall and get my name up there. In part to first say thanks for the site and forums, BITOG. I've been searching the web, and stumbling across articles on here for at least a year, and it has really helped me to understand significantly better. Specifically, I'd like to mention there was a really good article, perhaps written in a forum thread style, and maybe truly as a forum thread, that put to rest the reliance on K100 spec as the operating viscosity and how the HTHS 200 and viscosity index are better data to consider. I will have to find that link again and read it again already as I'm starting to forget the terms as you can see. It will be bookmarked and used as a reference in the future. To my question however...

I have a 2008 Grand Prix with the GM 3800 series/mark III motor. Currently it has 180k miles, and I've run synthetic in it since I got it with 12k miles. I live in northern Missouri. I drive a work vehicle daily, so this car sits until the weekends when I make an self-imposed obligatory trip just to get it out and warm it up, and keep it from developing flat spots on the tires. I absolutely will not short trip it when I do get it out. I will either skip a weekend or, (cringe) two weekends, but I will not drive it less than 50+ miles one-way to go somewhere and then return in the evening.

I have to admit that I am a meddler. I love fixing things that are not broken. Why I even ask on here is because I like seeing what others have to say, and perhaps will suggest something I have not already thought of. My question is what will happen if I use 10w30 conventional oil with SN and SN plus GF6A ratings, lacking Dexos, May 1 to September 30, before switching back to the recommend 5w30 spec specified in the manual, synthetic, and with Dexos rating?

Summer Plan (5-months; May thru September): Conventional 10w30 GF6A SN Plus (perhaps Castrol GTX)
Winter Plan (7-months; October thru April): Synthetic 5w30 GF6A SN Plus Dexos (PDS: https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_SB.pdf)
Alternative Winter Plan: Synthetic 0w30 as not starting more frequently than on the weekends seems to produce dry starts for the first second in sound on that first weekend startup, and perhaps a 0w would really help me out a lot there.

Additional Info: DIC (Dashboard Information Center) says that I've got 60% oil life remaining, current OCI is just over 6k miles, Aug 2023 (9-months +/-). And if someone tells me I could delay my oil change until after I put a big trip on the oil May 9, and drive 2,000 miles in four days, then I'd be willing to delay this until I get back, and then change the oil.

To directly answer your question of "What will happen?"... The answer is Nothing will happen. You will not have a problem.

The question from the rest of us to you is... Why bother switching between conventional 10W-30 and synthetic 5W-30? There is nothing to gain by switching back and forth. Just pick a flavor of oil and use that. Personally, I find it a lot easier to just buy synthetic 5W-30 on sale and keep it in the garage for the next oil change. Pennzoil has a nice $25 rebate running right now on two 5-qt jugs. Easy Peasy.

 

[Patman]

I've said this for a long time now that I feel as if 10w30 is somewhat of an obsolete viscosity because there are so many good 5w30s that can perform everything that a 10w30 can do, plus having the better cold cranking ability in the winter.

So my vote here would to be to choose a good 5w30 synthetic and run that all year round. Keep it simple.

 

[wpod]

0W-40 syn and change it once a year or 10,000 miles.

 

[thastinger]

If you're a meddler welcome to the world of meddlers. You'll unlikely find another automotive site with more meddling than BITOG.


Note: It takes months for soft high performance summer tires to flat spot. Tires will not flat spot over a weekend. IJS

Maybe he has TSL Boggers on it, those things will flat spot overnight.

 

[kschachn]

Perhaps Dru2u will return to this thread and give additional answers.

 

[Dru2u]

Thank you all for the responses! Your suggestions are heard and appreciated, and your points taken. I've got a followup question, but will first try to answer any questions that were put to me.

Why conventional? Why not just a thick synthetic?

Just a meddling point, perhaps a coping mechanism to try to control something.

I just enjoy doing things differently than most others, and learning in the process.

Where are you finding SN oil at?

Sorry, that was a mistake. The PDS of the linked product was SP. I just misread and forget most everything has now received SP certification if it is still on the shelves.

I've said this for a long time now that I feel as if 10w30 is somewhat of an obsolete viscosity because there are so many good 5w30s that can perform everything that a 10w30 can do, plus having the better cold cranking ability in the winter.

So my vote here would to be to choose a good 5w30 synthetic and run that all year round. Keep it simple.

I'd say this is a good, general statement, "obsolete." And it seems to be reflected on store shelves. You have to be deliberate to find the thin facing of 10w-30 and pull it out from between the 0w-20, 5w-20, 5w-30, 0w-40, and 5w-40 labels with their further multiples from variants within the brand for different roles (extended performance, high mileage), not to mention then the multiplication of the multiple brands that all have shelf space to do the same. The 10w-30 may appear from Mobil, Castrol, QS, and a store brand, but that's about it, and the Mobil may not even be present.

To answer the rest, I want to pit what seems the general consensus of getting a good 0w/5w-30 and running it year round, versus going for a XXw-40 as was suggested by JavierH19, goingplacesanddoingstuff, and wpod. I suspect several more might agree if I'm correct in assuming the XXw-40 came up because I'm getting up to operating temps for a good amount of time nearly every time I go somewhere with this car, that the 40 would increase protection for that extended warmed up period. Unless the assumption is that my car is getting older and may need something that doesn't lose too much viscocity and fail to provide the film need (I'm really questioning my knowledge to ask about this assumption this way). Perhaps it would be better to ask more simply, why have you guys thrown out a suggestion for something ending 40?

With that 40 thing, perhaps it would be good to just give you all a current stock of my inventory, and see where you would all go.

150 quarts (yes, a lot) - Excede 5w-30 Full Syn (https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_SB.pdf)
12 quarts - Excede 10w-40 (https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_10W-40.pdf)
12 quarts - Royal Purple 0w-40
10 quarts - Mobil1 5w-30 Full Syn

-- Deleted my comment about oil filters -- This isn't the right forum area for that, and it was merely a joke. I may go over to that forum to see what is said about filters at some point, but I'll probably just use up what I have for the vehicles I have before I look into changing that. --

Thanks folks!

 

[TomYoung]

Thank you all for the responses! Your suggestions are heard and appreciated, and your points taken. I've got a followup question, but will first try to answer any questions that were put to me.


Just a meddling point, perhaps a coping mechanism to try to control something.

I just enjoy doing things differently than most others, and learning in the process.



Sorry, that was a mistake. The PDS of the linked product was SP. I just misread and forget most everything has now received SP certification if it is still on the shelves.



I'd say this is a good, general statement, "obsolete." And it seems to be reflected on store shelves. You have to be deliberate to find the thin facing of 10w-30 and pull it out from between the 0w-20, 5w-20, 5w-30, 0w-40, and 5w-40 labels with their further multiples from variants within the brand for different roles (extended performance, high mileage), not to mention then the multiplication of the multiple brands that all have shelf space to do the same. The 10w-30 may appear from Mobil, Castrol, QS, and a store brand, but that's about it, and the Mobil may not even be present.

To answer the rest, I want to pit what seems the general consensus of getting a good 0w/5w-30 and running it year round, versus going for a XXw-40 as was suggested by JavierH19, goingplacesanddoingstuff, and wpod. I suspect several more might agree if I'm correct in assuming the XXw-40 came up because I'm getting up to operating temps for a good amount of time nearly every time I go somewhere with this car, that the 40 would increase protection for that extended warmed up period. Unless the assumption is that my car is getting older and may need something that doesn't lose too much viscocity and fail to provide the film need (I'm really questioning my knowledge to ask about this assumption this way). Perhaps it would be better to ask more simply, why have you guys thrown out a suggestion for something ending 40?

With that 40 thing, perhaps it would be good to just give you all a current stock of my inventory, and see where you would all go.

150 quarts (yes, a lot) - Excede 5w-30 Full Syn (https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_SB.pdf)
12 quarts - Excede 10w-40 (https://www.mfaoil.com/wp-content/uploads/MFA-Oil_Excede_10W-40.pdf)
12 quarts - Royal Purple 0w-40
10 quarts - Mobil1 5w-30 Full Syn

-- Deleted my comment about oil filters -- This isn't the right forum area for that, and it was merely a joke. I may go over to that forum to see what is said about filters at some point, but I'll probably just use up what I have for the vehicles I have before I look into changing that. --

Thanks folks!

You have two posts on BITOG, and you have posed a syn v. Conventional question, covered the eternal thin v thick battle, and contemplated whether a psychological pathology drives your choices. You then go on to reveal a doomsday prepper’s stash of oil, which would have us apoplectic, were it not for most of the inventory being from a lesser known manufacturer. Impressive!