Change Hyundai Oil Or Not ?

Going back to my early days of driving till now, If I have a trip, I always keep the old oil in and change it on my return as trips are EZ on oil.
I would check the level and perhaps use this trip to add a bottle of a good POE fuel injector cleaner as I also prefer to use those gas additive cleaners BEFOR I do a fresh oil change. My 2 cents...
I was going to say the same thing. I've always had more pronounced results from fuel system cleaners when driving for long periods. I've always felt that the cleaner works best at operating temps and a steady state of rpm (like highway driving). There may be a similar affect when the cleaner/fuel mix is simply sitting in the system cold and not flowing when the car is not running, but I'm not sure.

Either way, it makes the most sense to do it right before the oil change and not after. Any contaminates remaining from the fuel system cleaner will be removed in the fresh oil change.
 
Do you have a TSB number to share for that? This is on Hyundai website for 2017 Sonata 2.4L for every 3750 for severe service and 7500 for normal.
Screenshot at 2026-07-06 09-55-13 1.webp
 
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That TSB is more toward the Fuel system cleaner that they recommend using more than even Chevron does. Many here feel that even 1 bottle every OCI is pushing it and don't use it until end so if any dilution happens they get it back out. The Tucson and Sonata are the first I have seen in my helping many and owning many vehicles that actually recommend fuel additives.

Unless the fuel additive is getting past the regular rings I don't personally see where it will help oil consumption from stuck oil control rings. Can it get by, sure, that's why some do piston soaks but that is a specific procedure. The oil choice I think would be more impactful for oil burning issues versus any one of the fuel additive cleaners. The fuel cleaners should help keep injectors clean, hopefully some with carbon on pistons and other spots. Unfortunately on GDI it won't really do anything for the valves. On MPI or like some that are GDI/MPI combination (like '21 Sonata 2.5L) the FSC should help keep clean.

I agree and said that OP is probably in the mixed use so going longer until he returns should not be an issue and maybe longer than that. I also stand by the Hyundai/Kia motor issues and extended intervals may not be in our best interest. As long as they get through warranty is all Hyundai/Kia really worry about even with the extended mandated engine warranties from issues. After they pass that, it's all on us.

By the way thanks for the TSB#, I will print that TSB for daughters boyfriend with the '21 Sonata and probably tell him to stock up some on the Restore and Protect Fuel System Cleaner BOGO at Autozone. He wants to learn to help maintain it and I guided him through last oil change with VRP and Carquest Premium filter.
 
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FWIW, I'm a huge fan of Techron Complete but the results only happen in my cases from extended (2hrs minimum) high-speed freeway driving.

I've never gotten any noticeable results by following the proper add instructions, then bumping around in bumper to bumper city traffic for the entire tank of fuel.

I think it needs that steady higher rate of fuel delivery for longer durations to do it's thing. YMMV.
Way further back in the past I used to use Techron at least 2x per year, never noticed a difference in daily use of 75% highway. I thought I was just maintaining clean. I pretty much always use TT fuel from Exxon/Mobil, Shell, BP. One based on some other product use and recommendations I tried BG44k. That was basically what I had thought Techron was doing. In my same use conditions, working 6 days/week, MPG went up (documented), a bit more power from butt dyno and a bit smoother running. Of course just after that the MPG went back down but that from the nut behind the wheel. BG SynchroShift II fixed my light grinding from transmission, the power increase made driving more fun again = closer to redline shifts with the manual transmission. Trade offs. 🤭

I pretty much stopped using Techron since then.
 
That TSB is more toward the Fuel system cleaner that they recommend using more than even Chevron does. Many here feel that even 1 bottle every OCI is pushing it and don't use it until end so if any dilution happens they get it back out. The Tucson and Sonata are the first I have seen in my helping many and owning many vehicles that actually recommend fuel additives.
We're drifting a little off-topic here, but regarding Techron--the Owner's Manual for my 2018 Soul specifies:

For Customers who do not use TOP TIER Detergent Gasoline regularly, and have problems starting or the engine does not run smoothly, additives that you can buy separately may be added to the gasoline. If TOP TIER Detergent Gasoline is not available, one bottle of additive added to the fuel tank at 7,500 miles or every engine oil change is recommended. Additives are available from your authorized Kia dealer along with information on how to use them. Do not mix other additives.

I used to add Techron at every oil change, but have had motor oil reeking of it for the remainder of the OCI. Since I've always used Top Tier fuels, I now deploy Techron only on an as-needed basis, and my oil consumption has steadily declined since making this change. At 142,000 miles, I'm down to less than a quart added in 5000 miles.
 
We're drifting a little off-topic here, but regarding Techron--the Owner's Manual for my 2018 Soul specifies:

For Customers who do not use TOP TIER Detergent Gasoline regularly, and have problems starting or the engine does not run smoothly, additives that you can buy separately may be added to the gasoline. If TOP TIER Detergent Gasoline is not available, one bottle of additive added to the fuel tank at 7,500 miles or every engine oil change is recommended. Additives are available from your authorized Kia dealer along with information on how to use them. Do not mix other additives.

I used to add Techron at every oil change, but have had motor oil reeking of it for the remainder of the OCI. Since I've always used Top Tier fuels, I now deploy Techron only on an as-needed basis, and my oil consumption has steadily declined since making this change. At 142,000 miles, I'm down to less than a quart added in 5000 miles.
In my case I had a rough uneven idle, I suspect from months of short tripping and winter idling while waiting to pick my wife up from work. All the customary tune-up related parts were up to date and the car ran fine while driving, just idled like 💩 especially once warmed up idling at traffic lights in "D".

I had long suspected a failing IACV which is hard to source and very expensive for this car. I ran the large bottle (16oz) of Techron Complete through it and drove a 75mph trip, an hour each way. Since then (over a month ago) the car has ran and idled like new. I'll keep using the Techron if it provides results like this, I got a 4-pack from Amazon a while back for super cheap👍
 
Glad Techron worked for you, Legs4Arms. Were you using it regularly prior to your car developing a rough idle?
 
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