8500 Mile Trip Report

[Rey]

20014 Signature completed an 8533 mile trip from OR to FL the long way visiting friends and family. About 5% rough estimate was city stop/go/idle, which really affected gas mileage.
Highway speeds from 65mph to 85 mph - never more than speed limit plus 5 mph.
Oil consumption was less than a quart, maybe 8 oz.
Average speed city and highway was 54 mph.
Overall gas mileage was 24.5 mpg.
The Equus is a marvelous travel car. It does everything very well. On mountainous roads and freeway speeds above 70mph I use the "sport" suspension setting, which settles the suspension nicely.
Odometer reading at end of trip was just under 30K miles.
Hyundai seems to have fixed the oil consumption (blowby) problem that affects 2012 RSpec V8s (I owned one).
Gas mileage increased during this trip. At the beginning my gas tank computer range was about 420 mi. (highway). By the end of the trip it was 460+. I think this V8 motor is loosening up with mileage.
I an running Motorsport Authority secondary cat deletes which add some power and enhance gas mileage a bit. Also running Michelin low rolling resistance tires, which in my experience over many years seem to yield 0.5-0.75 mpg.
I buy the cheapest gas I can find - always "regular". No knocking ever heard.
I buy gas at Flying J or Pilot truck stops and sometimes Costco. These vendors not only have cheaper gas, but also their gas tends to be "fresher" because of their high volume. I have consistently received better gas mileage with regular vs. premium. Every once in a while I do back-to-back tests just to confirm.

 

[ASHDUMP]

20014 Signature completed an 8533 mile trip from OR to FL the long way visiting friends and family. About 5% rough estimate was city stop/go/idle, which really affected gas mileage.
Highway speeds from 65mph to 85 mph - never more than speed limit plus 5 mph.
Oil consumption was less than a quart, maybe 8 oz.
Average speed city and highway was 54 mph.
Overall gas mileage was 24.5 mpg.
The Equus is a marvelous travel car. It does everything very well. On mountainous roads and freeway speeds above 70mph I use the "sport" suspension setting, which settles the suspension nicely.
Odometer reading at end of trip was just under 30K miles.
Hyundai seems to have fixed the oil consumption (blowby) problem that affects 2012 RSpec V8s (I owned one).
Gas mileage increased during this trip. At the beginning my gas tank computer range was about 420 mi. (highway). By the end of the trip it was 460+. I think this V8 motor is loosening up with mileage.
I an running Motorsport Authority secondary cat deletes which add some power and enhance gas mileage a bit. Also running Michelin low rolling resistance tires, which in my experience over many years seem to yield 0.5-0.75 mpg.
I buy the cheapest gas I can find - always "regular". No knocking ever heard.
I buy gas at Flying J or Pilot truck stops and sometimes Costco. These vendors not only have cheaper gas, but also their gas tends to be "fresher" because of their high volume. I have consistently received better gas mileage with regular vs. premium. Every once in a while I do back-to-back tests just to confirm.

Nice write up. Sounds like you pay attention to your car so I'd like to get some input from you.

I have a 2014 signature like yourself however I've had issues since day one with smooth acceleration. I've had it back to Hyundai multiple times and haven't been able to fix the issue.

This sensation is more prevalent when the engine is cold and hitting the highway early. I can also feel this when the engine is warm however it is less noticeable.

The feeling has been described as a flutter/shutter or slight jerky. Its when smooth acceleration is accomplished from 50MPH to about 85MPH.

Do you notice any kind of shutter or flutter when accelerating when hitting the highway or back roads that allow you to get up to 65 70?

Possibly a sensation as if someone was pinching the gas line then releasing? I also get this sensation which is separate from the above sensation.

 

[Rey]

Ashdump,
Basically, the main variables on any motor are fuel, air and ignition.

I think you can generally rule out ignition, simply because it is "fixed". BUT, sometimes cars suffer early coil failure/low performance. Spark plugs usually work or don't work. Your dealer may be able to test.

That leaves fuel/air ratios. There are available fuel/air ratio meters, which test vis a vie exhaust gases. They were very expensive at one time. Price is now about $350. When the car starts from cold it is in the "open loop" fuel system which is effectively a modern "choke" and rich running. Soon thereafter the car switches to "closed loop" which maintains a constant 14.7:1 fuel/air ratio for steady state and mild acceleration. On heavy acceleration ("full stomp") it switches back to open loop, which then is essentially a fuel dump (rich). Point is that you can verify your fuel air ratio to confirm normal/abnormal.

Looking at your fuel system, you might try adding some Techron (avail cheap at Costco) for several tanks. I add three bottles after every oil change. This can help loosen a sticky fuel injector. You could have gotten a bad/filthy tank of gas which has clogged your fuel filter prematurely.

Check your air filters - there are two. I removed the little flap on the small "upper" air filter. I also modified the flap on the larger lower filter. I removed the magnet which really prevents the flap from opening in almost all conditions. Then I added a couple of washers (glued) to give it some weight. Now I have a bit more motor noise, but that is o.k. by me.

Something you can do at home is "reboot" your ECU. Your dealer has probably done this. Simply disconnect both batter leads from the battery and then hold them in contact together for about five minutes. This will take a jumper wire as there is not enough slack for them to connect otherwise.

If all checks out so far, then I would focus on the ECU and the transmission itself. The Hyundai eight speed has had some teething problems. I had two transmissions replaced in my '12 RSpec - more complete failure. One of the early complaints was slow/dead throttle response. No such problems on my Equus.

Finally, does your dealer agree a problem exists? If he does, then push up through the "chain of command" for a resolution. If your dealer is putting you off saying "they all do that, etc", then same push past dealer to customer service.

Best,

Rey

 

[Rey]

Another thought that may be more relevant to your acceleration problem: check your foot throttle assembly (accelerator pedal). Hyundai uses European technology for a wired throttle. The assembly is held by a single 10mm bolt. It is basically a sophisticated reostat. This technology is also used by BMW and others.
There were complaints on early 6 speed Genesis about slow throttle response. A Greek company, Sprint Booster, offered a "fix" consisting of a passive electronic filter which attaches to the throttle assembly. Cost $300. It was a good fix. I had it on two prior six speed Genesis. There are two models - manual and auto transmission. The manual model is more agressive and works just fine. There are three settings on the contraption - normal/stock, intermediate and advanced.

When the eight speed transmission came out it appeared to me that Hyundai fixed the complaint. For sometime Sprint Booster did not have an application for the eight speed, but I see there is now a listing for the eight speed.

On the same theme, you could ask your dealer to check out your throttle assembly. A simple expedient check is to temporarily swap in a throttle assembly from a new car.

 

[Aquineas]

Rey your trip-report was disappointingly short on places you visited, roads you liked, didn't like, great food-stops, etc.

 

[Rey]

Our trip was not a sightseeing trip per se. We traveled to see family and friends. Began in Salem, OR. Major stops were respectively, Whitefish, MT; Pierre, SD; St. Paul, MN; Brookfield, WS; Muncie, IN; Knoxville, TN; Alpharetta, GA; Tarpon Springs, FL; Captiva Island, FL; Houston, TX; Scottsdale, AZ and Santa Fe, NM.
I'm a geezer and have done long road trips since my teens, and still love to drive. I have an old road atlas in which I have highlighted all the roads driven. We've driven most east/west major highways one time or another. When we need to make distance we drive Interstates. But when time permits, we are on two lane roads.
Very fond of US12 across Montana. Check Steve's Cafe in Helena. Interior highways in Oregon have little traffic and are marvelous. When traveling we visit Cracker Barrel restaurants - great pancakes and salads. Also, Culvers for Walleye sandwiches and frozen custard. We usually stay at Marriott where I can still get a govt. rate. Breakfasts are included in most hotels these days. For lunch we tend away from franchise, except maybe Applebees. Diner is usually red meat and wine. Years ago when touring on a motorcycle we tried to spend more money on diner and wine than on the hotel. We have throttled back with age. We tend to initially judge local restaurants by the number of cars in the parking lot. Police cars in the lots are a sign of consistent good reasonably-priced food.
We are early risers, but it always takes my wife a full hour to dress,etc. I don't mind a bit as she is still beautiful. Our driving days vary in length, but coming home we often have longest days - like from Billings to Salem. On this trip we did Santa Fe to Salem in just one sleep - two long driving days.