Hypermiling a 2008 Kia Rondo--Quest for 30 mpg

[ISV-2K8Rondo]

I own a 2008 Kia Rondo LX. Most of the time my mileage in mixed driving has been 22-23 mpg (more or less EPA combined estimate) in the summer and 19-20 mpg in the winter.

Then I came across this site, lurked a little, then applied some "adjustment to the nut behind the wheel". Namely coasting to lights, keeping the speed down on the freeway, and DWL on hills. I was stunned to see 26.3 mpg, a result I usually only got on long trips. Then 26.9 mpg when I bumped the tire pressure from 35 to 40 psi. Then 27.4 mpg by using less A/C.

As a recent divorcee (note to those who've never experienced this--DON'T!!!!), single income = every cent counts. Needless to say, I'm happy I'm beating the EPA estimates by a healthy 20%+. A penny saved is NOT the same as a penny earned--it's worth MORE. You don't pay taxes on the former. Adding 4-5 mpg is like a pay raise when you're putting an average of nearly 40 miles/day on your car.

It'd be cool to see that first number on the mileage be a 3 instead of a 2. The magic 30. I've only seen about 28.5 mpg, and that was on the highway. But where to go from here? I'm thinking of getting the Scan Guage at some point.

I like the way this train's going, but I don't want it to stop, so it was time to do my first eco-mod. I fully confess. I whacked the roof rack on my 2008 Kia Rondo LX. More specifically, the cross beams on the roof rack. No remorse. No guilt to assuage later on. Dealt a fatal blow with Tony Soprano-like coldness. And truth is, it had it coming. (well, actually, just set aside in the garage. Okay; I'm milked the metaphor too much)

Roof racks--even empty ones--will increase drag. That certainly didn't help it's case, but in addition, it is a royal pain sweeping snow off the roof with those blasted cross beams!! And here in NE Ohio, we have two seasons--construction, and winter.

I don't know what to expect in terms of increased fuel economy from whacking the rack. I read the Edmunds article where a 2008 Buick Enclave had a 1% fuel economy increase with the roof rack removed...but that's a LARGE vehicle, about 50% heavier than my Rondo. I saw the Consumer Reports article on the 2013 Honda Accord which had a 14% boost @ 65 mph with no roof rack vs. empty roof rack.

So my goal with this car is simple--30 miles/gal (U.S.), or 7.8 L/100 km. I'm keeping the tires around 40 psi (max sidewall 44 psi), minimizing A/C, and removed the rack cross beams. I've already heard suggestions of grille blocks; considering that for the upcoming winter.

Further suggestions would be greatly appreciated, particularly priority lists for this kind of car.

Thanks in advance,
Phil

[puddleglum]

Great start. These cars are not easy to hypermile but it can be done with some work. buy a Scanguage or something comparable. Throttle input is extremely sensitive and keep your speed down on the highway. I recently got 6.67l/100 for over 600miles on a recent highway trip with about 500lb load. All city will be much harder but I think you can do it.

[ISV-2K8Rondo]

You mentioned the Rondo having a sensitive throttle input. Is there a BSFC graph for this particular engine? I've scoured the web for one but can't find it.

As far as acceleration goes, I've been keeping it around 2,000-2,100 RPM before hitting 5th gear. I think, if anything, I'm too light on the accelerator, as it takes over 20 seconds to hit 5th gear (typically 42-44 mph, or 70 km/h). In my suburban stretches I have about a mile (1.6km) between traffic lights, and I can't but think I'm losing some fuel economy by reducing the % driving time in high gear. Maybe 2,200 - 2,300 RPM when accelerating? Good/bad idea?

--Phil

[JRMichler]

This is where a Scangauge/Ultragauge pays off. Use the trip mileage gauge to get the average MPG from a stop (reset to zero) to a fixed point down the road. Accelerate to the same speed every time, but at different rates. Make sure that you are traveling at the same speed when you pass the fixed point. The acceleration that gives you the best MPG at that point is the optimum for your vehicle.

My truck gets the best MPG when I step the gas pedal about 2/3 down and shift at 2500 RPM. That acceleration is similar to everybody else, so I'm moving with traffic.

Be aware that ambient temperature, engine temperature, and wind will all affect your results.

[puddleglum]

Looks like you have the V6, mine is a 4 cyl. so it may not react exactly the same but mileage is pretty similar for both. Being able to view instant mpg is extremely important for the above reasons and more. It is virtually impossible to tell the difference between 20 and 35 mpg with your foot. I have never seen a fuel graph, this is a family car remember, but I find in mine that I do better accelerating with traffic. I found revving to 2500 ish works better for me. The engine seems to use about the same fuel getting up to speed but for less time. Then I let right off and try to just barely maintain speed with a little pulse here and there if it drops off. My wife drives the car mostly during the week now so there isn't much hypermiling gets done anymore.

[puddleglum]

As for mods, with winter coming I suggest you focus on keeping it warm. If you don't have a block heater, install one and use it at anything below about 35-40F. Temro makes one for it (don't know the number but you can google it) but I can't tell you exactly where it mounts on the v6. IIRC both engines take the same block heater and it is a dry fit so super easy to install. You might be able still get one from a Canadian dealer, not sure. Also, do a grill block and possibly consider a front belly pan. It will keep the engine bay warmer and help with Aero as well. I run my upper grill block all year around and have a full belly pan. In winter I keep part of the lower grill covered as well, but I watch the temps pretty close. I totally deleted the roof rails on mine. It won't pay for itself ( the cross bars are the big air drag) but it makes the car feel lower when sweeping the snow off and I think it looks better.

[ISV-2K8Rondo]

I actually have the 2.4-L 4-cyl version like yours, only one model year later. More or less the same car.

I will soon get a thermometer to put out in the garage. I'm curious as to what the temperatures will drop to in wintertime. We are not as cold here in northern Ohio as Alberta, but winters around here are cold enough; typically 2°C high / -6°C low for a three-month Dec-Feb average. Coldest temps in any given winter are typically -18°C to -20°C.

[puddleglum]

Okay, the comment about 5th gear threw me as the I4 only has a 4 speed and the V6 has the 5 speed. Anyway, I still think you will benefit from the mods I said above. There are guys on here that use a block heater up to 20C but I don't go that far. I haven't seen enough savings to justify the cost of electricity. Still, it is said 90% of engine wear comes during warm up so anything to help your engine warm up faster is going to make your engine last longer but that is hard to quantify. It is definetely colder than that here. I've already had frost on the windshield last week. Winters usually range from -10C to -30C. Sometimes we'll get a day or two of -35 to-40C and sometimes it can jump up above freezing for a few days as well. When it's really cold I block the entire grill and I run a oil pan heater and transmission heater along with the block heater. All our in town trips are short so warm up is very important.

[ISV-2K8Rondo]

Yeah, it's a 4-speed; my bad.

What would a decent size heater for this be, around 500W? I'm thinking at 3 hr/night, I'd only consume an extra 45 kWh per month if I had it on every night. At $0.128/kWh, that's $6/month extra electricity. That's not much. I'm saving way more than per month with hypermiling techniques.

Incidentally, I just bought this house in July, and my first home project was replacing all the house's incandescent bulbs with LED's. That alone clipped $20/month off my power bill, and since the home is heated by natural gas, my winter power bills shouldn't be that scary if I have to run a block heater.

[puddleglum]

I think the factory heater is 400watts and it'll only need 2-3 hours if your temps aren't too severe. You can buy a cheap timer and program it to come on before you have go to work or whatever and the cost is very little, maybe $0.10/ heat cycle.