You’re expert advise on Hyundai GDI: NEW with High mileage, 75% city, high idle time

If you are planning to keep it, then I'd do the 3k OCI as putzing around the city and then lots of idle on top of that, is severe service IMO.
5W30 syn of whatever flavor you like is going to be fine.
 
On my 2021 K5 AWD I use 5W30 in the summer and 5W20 in the winter. I have used 0W20 in the winter for a few oil changes. My stash includes any of the major brands that i have got on sale although about half of my 20 jugs are Penzoil. I set the interval at 6000 km. I traded my 2011 Optima with the 2.4 engine to get the K5. The Optima was the most reliable car I ever owned until the K5
 
Stop talking. No GDI Kia motor can do 10k OCI.
Well that was polite. Sort of Thunderous. My guess is that this GDI is almost always under power, with some idling to boot, at 60k a year. Almost like taxi service. Watch the oil level for any increase and change the oil every 6-8 weeks, 10k miles. Get a UOA after the first 10k run and adjust accordingly.
 
I have that engine. I use 5-40 Quaker State European formula. I change at about 4,500 miles. Fram or OEM oil filter will do. I also use a GDI intake valve cleaner at least once a year. I recently used the Berryman system which I like a lot. I would never go beyond 5K on an oc. I currently have about 85K on the car and runs sweet. I also change the spark plugs as in the maintenance schedule. Techron or Gumout high mileage twice a year in the tank. I also run 89 octane fuel. The recommended 87 does not do well for the engine.

IMG-5529(1).jpg
 
Last edited:
Well that was polite. Sort of Thunderous. My guess is that this GDI is almost always under power, with some idling to boot, at 60k a year. Almost like taxi service. Watch the oil level for any increase and change the oil every 6-8 weeks, 10k miles. Get a UOA after the first 10k run and adjust accordingly.
Don’t do 10,000 miles period the end.
 
Y’all seem to know your stuff over here. I’ve been going down the oil rabbbit hole for a couple months but for the first time ever, I’ve succumb to information overload and realizing there are many many factors to consider what oil will serve me best, yet only a handful of options to pick from so no need to o er think. Im now reduced to the point where I can’t think anymore and accept I’d be better off hearing y’all’s opinion.

What would you run for oil?
What would you use for additives?
How often oil flush? Or would you do at all?

2021 Kia k5 GT-line
1.6 turbo GDI Gamma (II or iii)
50-60,000 miles per year
75% or so city driving. I’m probably exaggerating there but it’s heavy for sure.
And lots of idle between drives. I’ll turn car off weather permitting.

Thank you. I already feel less weight on my shoulder. Very much appreciate the wisdom in the forum.
A Hyundai / KIA GDI 1.6 Turbo ? 5W30 Synthetic D1/Gen 3 rated oil , Fram Ultra Oil Filter . It's a GDI so it will produce a lot of soot in the oil and it's a turbo so pretty hard on the oil . Use owner's manual severe service schedule for oil change (approx. 4,000 mile OCI).
 
Well that was polite. Sort of Thunderous. My guess is that this GDI is almost always under power, with some idling to boot, at 60k a year. Almost like taxi service. Watch the oil level for any increase and change the oil every 6-8 weeks, 10k miles. Get a UOA after the first 10k run and adjust accordingly.
I have no reason to be nice. You're giving objectively bad advice
 
Last edited:
Like every turbo'd engine it likely suffers from too much exhaust pressure.
IMO, a cat-back exhaust system would pay for its self in fuel economy improvement
and cure the gasoline in the oil problem. If it exists at all.

Obviously you can do seasonal adjustments to the grade of oil.
Thicker in the summer than winter, or at least the appropiate W grade for ambient.
xW40 would be my starting point for extended drain intervals.
 
Like every turbo'd engine it likely suffers from too much exhaust pressure.
IMO, a cat-back exhaust system would pay for its self in fuel economy improvement
and cure the gasoline in the oil problem. If it exists at all.

Obviously you can do seasonal adjustments to the grade of oil.
Thicker in the summer than winter, or at least the appropiate W grade for ambient.
xW40 would be my starting point for extended drain intervals.
In the winter you would need the thicker 40 due to the increase of fuel in the oil.
Turbo, GDI, Low tension piston rings+cold city driving=lots of fuel in the oil.......lots.
 
The GDI feature causes dirty intake because gas isn't sprayed into it as with MPFI.
It's the PCV vapors which condense and accumulate...and are cooked into a hard-to-remove crud.
Are borescope ports ever designed into these intake systems so owners can just look in?
That would remove some of this OCI guesswork.
 
Back
Top