Fuel guzzler? is this so, or is mine not tuned right?

[SoyJet]

I was 'sold' that the 2.0 turbo did 30mpg on highways... I drive a highway to and from work, so basically my driving is 80% highway, flat, straight, so.fla expressway driving, no bad trafic; still, I cannot get more than 21 avg mpg...
I've owned it four months, and I took it in after two, and they said to 'log' it purhasing from same pump, and calculating actual mileage: it gave me 19.8 mpg. Then they said it'd get better after a few months. It hasn't.

I'm taking it back coz the odometer, actually the avg mi per h has been stuck at 41 mph since forever? I can't be sure if this was so from the begining or when. But as I will be taking it in, I'd like to know if there's something they can check to ensure that the car is tuned right (max boost, or whatever--no knowledge of cars... had a celica 01 till totalled... )

Pls someone tell me if this is the normal fuel consumption, or something is wrong with mine. I mean, it says 30mpg and I'm getting 21? too much difference. And I drive fast but like an old lady, not sporty or anything, just like a sedan. I bought the car coz I love the look...

 

[2011bh380]

I think the mileage really depends on the person in most cases. My wife and I both drive her Genesis. My wife averages about 5-6 mpg less than when I do. She's around 18.0-19.0 mpg and I'm usually around 24-25 mpg and we both drive in traffic. We both speed around the same but I noticed it seems to make a siginificant difference on how often you stop, go, and how hard you push either one. she likes to decently floor it to get it up to speed. I like to ease up to speed. When it comes to stopping, she is on the gas until she needs to stop. I like to coast to a stop without my foot on the gas constantly so I don't have to over exert the brakes when stopping. I guess I kind of treat it like a manual shift vehicle when you down shift to slow down. I let the automatic transmission on the genesis slow me down. She also likes to somewhat "tailgate" which increases the frequency of starting and stopping. I leave a minimum 4-5 second distance between the front car and me.

More frequent stop, go, coast(foot barely on gas, minimal coast(foot constantly applying decent or more pressure on gas), etc. seems to greatly affect mileage. At least for same genesis, two different drivers, similar driving conditions but same route .

I hope this information helped out.

 

[lee4697]

It can also be the fuel your putting in. i put in 91 octane cause thats the highest available to me. I noticed a huge increase when i switched to 87 to 91 especially on a long trip with little to no traffic.

If your going around 60 mph which is what the 30mpg is referring to there is no reason why you shouldn't be near the advertised mpg.

so long story short. 91 octane or higher, depending on availability and cruise at 60mph.

 

[krunchy]

If the average speed has been stuck at 41 mph for a while it might be that there is something wrong with the trip computer. Have you been calculating your MPG by using the odometer and the amount of gas you put in at each fill up or are you relying on the trip computer to tell you? If the trip computer is messed up then it will give you wrong MPG data. Best to use old fashioned math to check....

 

[SoyJet]

I actually drive it like a sedan... leave space between car in front, don't like stop and go, just smooth sailing... and as I said, it's all highway except one light before I get into the hwy and one light after, my work commute... traffic does not slow down, always going, so no bad traffic...

I took it to the shop last Wed for interference on my radio, they said it was the window tinting they 'gave' me... so they loaned me a genesis 4.6 (yes, sedan, so it is different, but a 4.6 !!!) which is doing approximately 24-25 mpg same road, same commute... I never heard of a 4.6 making better mileage than a 2.0... did you???

I've had it four days now, coz of course, the problem was not the window tinting and now they gotta replace the whole window for some reason... I told them I heard a screw or nut tripsying around in front be it under the hood or behind the dash, but they didn't seem to hear me, they think I'm fantasizing or something, and that it has nothing to do with it... I'm sure that's what it is causing the interference, something got loose, but... dealerships! if the computer doesn't say UUPS! then all is ok..

In any case... can someone tell me when exactly does the turbo kick in? how can I know? Am I running on turbe continuously, or only upon hitting the gas or sharp speed increases, or ???? can someone tell me this? Maybe the turbo is just going on for too long or something?

 

[Soledad]

I'm not extremely familiar with the 2.0's but I'm almost sure they have a boost gauge. If you are above 0 on the boost gauge then the turbo is "kicking in" and you are using more fuel. The best fuel mileage will come from keeping the boost gauge at or below 0 even when taking off from a stand still.

 

[mikec]

The turbo is always active to some extent; it's internal RPMs are a function of how much exhaust is flowing out of the engine. So when the engine is making big horsepower (accelerating or high speed driving, up hill driving, etc) the turbo will be more active. For around-town putt-putt driving the engine doesn't have to make much horsepower (thus your foot is depressing the throttle only a little bit) so there isn't a lot of exhaust flow... and thus little turbo activity.

For putt-putt driving, the fuel quantity fed to an engine is always a function of how much air the engine is consuming - turbo or non-turbo engines - so, when making "putt-putt" horsepower the turbo engine should be consuming about the same air, and thus the same fuel, as a non-turbo engine. There are two "penalties" associated with turbos though that will make them use slightly more air, and thus more fuel, at these part-throttle putt-putt conditions:
1: the turbo does block/restrict the exhaust a little bit... so the pistons have to work harder to shove the exhaust out. That extra work is wasted horsepower, just like the heat dumped out of the radiator is wasted energy.

2: to reduce the chances of knocking/pinging/pre-ignition caused by turbo boost pressure, most turbo engines are built with a lower compression ratio than their non-turbo counterparts. Basic thermodynamics says efficiency of an internal combustion engine increases as compression ratio increases... so lowering the compression ratio to compensate for turbo boost causes a slight loss in efficiency. The overall efficiency "gain" due to the turbo, compared to a larger non-turbo engine making the same horsepower, should be positive though: the smaller turbo engine has less internal friction and other things that lead to losses.

Modern turbo engines use sensors to detect knock/pinging (actually, even non-turbo engines do this now) and adjust (retard) the ignition timing to reduce it. Retarding ignition timing lowers the overall efficiency. If there is a problem with the knock sensor on your car the engine computer may be thinking "lots of knock" and thus it could be retarding the timing a LOT. It may not set a "check engine" light either - this type of reaction is common with poor quality (low octane) gas... so maybe your ECU thinks you're feeding it crap gas and it's correctly responding - ergo no check engine light.

A too-tight turbo will also restrict the exhaust a lot. With the engine OFF and stone-cold (overnight cold) it should be possible to remove the air duct going into the turbo compressor side (NOT the side bolted to the exhaust stuff) and you'll see the turbo compressor wheel. Usually there is a small nut holding the wheel to the turbo's shaft... grab that nut and try spinning the turbo. If it's fairly hard to turn, the turbo is tight and needs to be repaired/replaced. I don't have a Genesis Coupe turbo... but I do have an older Mitsubishi Starion turbo engine and that turbo can be spun like a child's toy top - it spins easily and will coast several revolutions on its own afterwords.

mike c.

 

[lee4697]

I'm not extremely familiar with the 2.0's but I'm almost sure they have a boost gauge. If you are above 0 on the boost gauge then the turbo is "kicking in" and you are using more fuel. The best fuel mileage will come from keeping the boost gauge at or below 0 even when taking off from a stand still.

Hahaha, nah the 2.0 doesn't come with a boost gauge. But if your still having trouble and the dealership can't figure out whats wrong then just do a silencer delete.

Dont know what your opinion is about having turbo noise but I like it. Here is a video on how to do it. Difficulty on a scale from 1-5 is a 1 so give it a try. If you don't like it switch back, takes about 15-20 minutes.

After I did this and got a 3" exhaust/downpipe my MPG went even higher, I avg around 32-35 mpg on the freeway when cruising at 70 now.

The silencer delete will allow your turbo to breathe easier and so allow it to use a little more of its potential.

heres the link i used to do the silencer delete

[ame="http://www.youtube.com/watch?v=CA_j-qyiHsY"]YouTube - 2.0T Hyundai Genesis Intake Mods[/ame]

 

[SoyJet]

Last night I picked up my car from the dealer: I'd taken it in due to radio interference caused by window tinting? they ended up replacing the whole glass. In any case, driving from the shop to work, and then home, the car was only showing 10 mpg... and it sounded forced... so I tried stepping on the gas sharply and letting go a couple of times, to see if maybe it got stuck somehow... but it continued feeling as a truck. Then I put it in manual; I was going at 70 mph or so, and the manual went in at 4 drive!!!!!! so I assume the transmission got stuck and that is why it was running sooo heavy duty... is this normal??? I had never used the manual coz I've never been good with stick shifts, even though I've had two shift-stick cars for several years, when I lived in Europe, and my first car here in the US... I don't like manual, just not good at shifting at the appropriate times... kinda what this car is doing, I imagine...
Any way, is this normal? if I'm going at 70 mpg and switch to manual, shouldn't it go in at 5????

 

[SoyJet]

hey, mike, lee, thanks !!!

Mike, I'll be checking it out, it sounds like something that may be causisng my issues.

Lee, I would love to say I'm going to do this silencer thing, but even though I'm good with my hands, I've never played with cars... not my thing. I'll save it though for when I get a new car-savvy boyfriend or something... lol!

Any other suggestions?

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[lee4697]

No problem. And yeah the silencer delete is really easy so just try it on a boring day LOL. Only thing you'd need a guy for is probably the extra muscle.

Regarding MPG nothing really. I mean If you think its the transmission or the turbo thats the issue, your best bet is to just bring it into the dealership and let them take care of it.

With the warranty you should have no problems and I believe is safe to guess you didn't do any mods so they'll have no excuse to try an say its not covered.

Sucks you got an odd ball car. I hear there are cars that have insanely more hp then they should stock so i guess theres a yin to every yang LOL

Our cars have issue with Fifth gear grind and when its cold its almost impossible to put into second gear. But those are all manual transmission issues.

So long story short, best of luck with the dealership in your area. Hope you got a better one then I do in Riverside lol (definition of "stealership")

 

[lee4697]

Oh and another thing you can do that I seen work for others is just drive in sport mode to begin with.

http://www.Genesis Coupe.com/2-0t/53815-f-ck-every-one-those-threads-complaing-about-mpgs.html

 

[Lambda2]

Last night I picked up my car from the dealer: I'd taken it in due to radio interference caused by window tinting? they ended up replacing the whole glass. In any case, driving from the shop to work, and then home, the car was only showing 10 mpg... and it sounded forced... so I tried stepping on the gas sharply and letting go a couple of times, to see if maybe it got stuck somehow... but it continued feeling as a truck. Then I put it in manual; I was going at 70 mph or so, and the manual went in at 4 drive!!!!!! so I assume the transmission got stuck and that is why it was running sooo heavy duty... is this normal??? I had never used the manual coz I've never been good with stick shifts, even though I've had two shift-stick cars for several years, when I lived in Europe, and my first car here in the US... I don't like manual, just not good at shifting at the appropriate times... kinda what this car is doing, I imagine...
Any way, is this normal? if I'm going at 70 mpg and switch to manual, shouldn't it go in at 5????

You might be driving around in the sport mode (manual) and not knowing it or the transmission on the car is messed up. If the car feels like it is being forced then you are probably driving around in low gears. What RPM range are you driving at? What I think is happening is the car is in sport mode and the car to shifting at the limits. This would explain the terrible driving experience and the poor gas milage.

 

[drgoochmobile]

I was really glad to see this thread because mine Genesis 2.0T also has been bad on gas. I'm in Canada so I measure in KM/Litre. I've checked twice now (trip computer -- will try that odometer method) and I am getting around 7 km/litre, which is apparently 16 miles per gallon so you're doing well! I've had the car about a month. Guess I might need to take it in.