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What type of Gas do you use in your 2015

Koolhaas

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I read the manual and it sounds like the 3.8 can take regular. My car is new and I haven't put gas in it yet. I only fill up once every two weeks, and it's almost time.

What do you guys put in your 3.8?

(the manual said the 5.0 can take 3.8, but for optimum performance should take premium)

What are your town's gas ratings? Mine are Regular - 87, Plus - 89(or91), and Super - 91(or93)

My wife's x5 recommends 91 or higher, so the mid-grade at the shell by our house is cheaper than the Premium Grade at Costco (costco only has regular and premium, no middle grade)
 
My 3.8 is tuned for regular 87 gas so I put in 87. I try to get gas from tier 1 stations whenever I can and clean the system with techron right before oil change.
 
My car only tastes Shell 87. Or Mobil 87 if a Shell isn't near by.
 
okay, I'm glad I understood the owners manual right. It just seemed a bit unclear. I'd rather put 87, but if need 89 or higher than I wanted to put in what works best.

87 it is!
 
GDI engines should not be run on lower octane, lower tier gas simply for the sake of maintenance. If you can help it at least. Direct injection engines develop build up on the valves and you want to minimize this because the only way to clean them is to pull the valves and have them media blasted. BMW, for example, says this should be done every 30k miles as this can affect performance, driving experience, and cause misfires eventually. Hyundai does not have this anywhere on their maintenance schedule, but that is an oversight on their part, not because they found a magical solution around it since ALL GDI engines across makes have this issue.

There are 2 ways to stave this off:
1. A good air-oil separator. Less blow-by means less to accumulate on the valves.
2. Top tier (list of companies that are certified:http://www.toptiergas.com/retailers.html) premium fuel. Cleaner burning so less to accumulate.

While direct injection is good for performance, it does have its downfalls.
 
I use only Mobil Super Unleaded in my 5.0. Zero issues. Top Tier gasoline...
 
GDI engines should not be run on lower octane, lower tier gas simply for the sake of maintenance. If you can help it at least. Direct injection engines develop build up on the valves and you want to minimize this because the only way to clean them is to pull the valves and have them media blasted. BMW, for example, says this should be done every 30k miles as this can affect performance, driving experience, and cause misfires eventually. Hyundai does not have this anywhere on their maintenance schedule, but that is an oversight on their part, not because they found a magical solution around it since ALL GDI engines across makes have this issue.

There are 2 ways to stave this off:
1. A good air-oil separator. Less blow-by means less to accumulate on the valves.
2. Top tier (list of companies that are certified:http://www.toptiergas.com/retailers.html) premium fuel. Cleaner burning so less to accumulate.

While direct injection is good for performance, it does have its downfalls.

is the 3.8 a GDI? What kind of gas do you use?
 
if i read the manual correctly...the 3.8l will run just fine on 87 octane...but does get a slight bump in hp/torque if using high octane like say 91.
 
if i read the manual correctly...the 3.8l will run just fine on 87 octane...but does get a slight bump in hp/torque if using high octane like say 91.
First I've heard of that for the 3.8. Can you provide the model year and manual page?
 
i buy 87, one of the reasons i bought the car was bc of that
 
There's no need to put anything beyond 87 , is a wasted of money. Unless you could prove other wise
 
I run Premium (91) in my car for a couple reasons.
1. It probably doesn't need it but every other recent variant of the Hyundai Lambda II seems to benefit from it so maybe it is more wishful thinking.

2. The additives in the premium blend (Kroger - I think it's Shell in my area) will probably burn a little cleaner in a GDI plus with the Kroger fuel points we rarely pay more than regular unleaded price. Makes me feel better too since we usually keep cars until the wheels fall off. My 2011 Sonata Turbo had 96,000 miles on it when we got Genny.
 
I use to put regular, but i noticed more smoke coming out of the pipes. So I tried premium and there isnt as much. Doesn't know if that was what caused it, but meh. I hate all the dirt buildup on the back of my car. So I only put premium now.
 
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First I've heard of that for the 3.8. Can you provide the model year and manual page?

this is for the 3.8l in the 2015 genesis

http://www.hyundainews.com/us/en/models/genesis/2015/overview

quote from that link:
"DIRECT-INJECTED LAMBDA 3.8-LITER ENGINE
The Genesis 3.8-liter direct-injected Lambda engine has also been further optimized to deliver a flatter overall torque curve at low rpm for enhanced driveability. Thoroughly improved for the new Genesis, this engine includes a three-stage variable intake system, triangular-pattern fuel injector for improved combustion, an air-gap exhaust manifold for better NVH, and an upgraded cylinder block with a variable-vane 2-stage oil pump for reduced parasitic losses. In keeping with its 5.0-liter V8 sibling, the Genesis 3.8-liter Lambda engine utilizes direct-injection and produces 311 horsepower at 6,000 rpm and 293 lb.-ft. of torque at 5,000 rpm. It also has a high compression ratio of 11.5:1 for greater thermal efficiency. The Lambda engine will run on regular fuel with only a small reduction in peak power, and no negative driving effects, whenever desired by the owner."
 
I run my 2015 3.8 with Shell or Mobil 87 Octane. I went 3 tanks with 93 and didn't notice much of a different in gas mileage or performance, so I went back to the 87. Most important is to use top tier gas; Shell, Exxon/ Mobil, Chevron. Actually, Costco is very good too. they meet or exceed what the big 3 do with their gas.
 
I use to put regular, but i noticed more smoke coming out of the pipes. So I tried premium and there isnt as much. Doesn't know if that was what caused it, but meh. I hate all the dirt buildup on the back of my car. So I only put premium now.

+1

I've never had that happen with the Genesis as I've always run premium in it but in the Sonata I ran 87 several tanks in a row when gas was sky high (the turbo was like the 5.0 where 87 was allowed but Premium preferred) and the tail pipes were covered in soot.
 
I usually run Chevron 87 octane which contains Techron.
 
87 only.... One of the most important selling points for me. I had 2 Infiniti's (G35 & G37) that took premium. Ugh...
 
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