Gas mileage

Replies to This Discussion

Permalink Reply by 451 Kahn on July 16, 2008 at 10:04pm

I think taking it easy on the Gas pedal should help.

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Permalink Reply by mr bad example on July 16, 2008 at 10:54pm

i think we have to consider what is "taking it easy, is". maybe some smarties were previous "lead foots" in a previous life. used to V6-V8 performance in their last car.

i drove 3 cylinder tiny cars for the last 20 years, i know what to expect in performance from a 3 banger (a metro is about the same weight as a smart) and drive it as such, merging is better in the smart, but i rarely need the OOMPH!

some new smarties may be driving the smart like they drove a V6-V8, getting the performance close to their older car, but dumping their milage down the drain. this
is what i'm thinking. i've had a "3 cylinder" mentality for 20 years, the smart has the
highest HP of the 3 i've had.

this is my thought, smarts get better MPG when you accellerate slowly. get used to going SLOWER. nature of the beast. i get better MPG than a local with a 450 (he didn't even know his engine size!) i was getting better MPG with a 451 than this guy with a 2006 450 turbo, he drives too quick/fast (he paid $30K+ for his smart, his other cars are faster, he just likes to go fast!) (i drove like a demon to catch him after i saw him!)

milage is a mindset. i'm keeping mine at mid 40's for local driving (43-47) and can get over 50mpg on the highway.

it's a mentality, they're used to going 0-60 in 6-7 seconds, and they're use to cruising at 60-70mph.

get on ASAP, stay in the right lane, and lock it at 55mph (some states have 45mph minimums) if you got the nerve, ride it at 45mph, if you have the time.

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Permalink Reply by slojason on July 17, 2008 at 12:53am

The post I have pasted below, plus using a scangauge, has helped me the most. Paragraph six gets to the heart of the matter. I get 37 combined if I drive like a normal car, 40 - 44 if I really pay attention and I've topped out at 50.4. The least I have ever experienced was the first couple of tanks at about 31 mpg. I've just filled up for the first time with regular, so we'll see what that does. I agree with the other posts; something doesn't seem right with your little smart. Good luck.

By Rick Masters on http://www.451s.com

The biggest key to high mileage in the Smart is probably understanding the transmission. A lot of people - and a lot of journalists who should know better (and even some dealer reps!) - seem to think the Smart has an automatic transmission and it has a problem of being too slow between gears. But that's not the case at all. The Smart has a manual transmission with an automatic clutch that shifts according to an optimized high mileage program. It is marvelous and it works perfectly. It even allows you to defeat the high mileage overlay with manual shifting similar to a Tiptronic that you find in high end sports cars and sports sedans.

This is the first transmission I have ever seen that is designed to do this. It even took me a while to figure out what it was. I was also under the illusion that the transmission was faulty in some way. I was even told at the dealer that I should lift my foot between shifts for proper operation. That is not the case.

One can make the Smart behave like a performance car and impress people who think its really cool to go fast and waste energy. I've been there, done that, and if that's where you want to be, there are a lot of cars that will make you very happy and do a much better job than the Smart. This is because the Smart was designed to go a long way on a tank of gas. That was the primary design goal, urban or highway. That's why I bought it. I'm a hyper-miler.

Most of all, the Smart reminds me of big, big trucks. Not in size, of course, but the way it shifts. some of you have probably driven big trucks. Big two axle, three axle, maybe some eighteen wheelers with 5 axles. Possibly a few of you pulled the heaviest 5-axle jobs, bulk liquids with a gross vehicle weight of 80,000 pounds. But I'm talking about the trucks I drove in the western states. Supertrains. Tank trucks with two trailers. 9 axles. 34 wheels. 120 thousand pounds. 105 feet long. Big, big trucks. Over mountains. Big, big mountains.

Those trucks are so heavy you don't use a clutch. You'd burn it up in one trip. Instead, you dog clutch through all 15 or 20 gears. That's right. You put it in low gear and drop the clutch at idle to get going. The flywheel gives you the momentum to start moving. Not the engine. Not the clutch slipping. From there on, you never touch the clutch again. You match the gears. You match the gears perfectly for every shift, for thousands of shifts. You pull through the torque curve, let off the accelerator, slip the shift lever into neutral, drop the revs to the insertion point for the next lower ratio gear, slip into perfect engagement, give it throttle, then repeat the process. You don't rely on the synchros to make your shifts work. Pros like me use the tach to slip the transmission teeth in neatly. We know every shift point for every gear, up shift or down shift. Our lives depend on it. So do yours if you are on the highway with us.

Anyway, I don't do that anymore. But the Smart shifts like that. Try it. Put the transmission in D and give the Smart a tiny bit of gas and lock your foot against the carpet to the right of the pedal to hold it in place. Don't move it. Moving the pedal wastes gasoline. The Smart knows what to do to give you the best economy possible. It moves you up through first gear, stops delivering fuel to the engine (even though your pedal's down), gives the engine just a little fuel to match the revs for the next gear, smoothly engages the teeth, then brings the power up to your pedal setting and repeats the process through all five gears.

To this old truck driver, that is not a fault. That is magnificent technology, perfectly applied for optimum economy and power delivery. It is hard to improve on that but you can really screw it up by not understanding it.

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Permalink Reply by Triock91 on July 17, 2008 at 2:28am

I am averaging 45 to 55 and that is in the city, and highway mixed.
I dont know whats going on with yours, Low tire pressure, are you getting enough air to your engine?

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Permalink Reply by Jim Mottin on July 17, 2008 at 12:54pm

am no expert so I am a bit hesitant to offer advice on this topic, but here goes. I see nothing wrong with going to a dealer, or elsewhere for a second opinion, to have a car checked over with reference to disappointing mileage. There are a number of things that can effect mileage that can be checked. However, at the same time I sometimes have difficulty appreciating mileage comparisons made by individuals when comparisons are being made for cars driven under different conditions by different drivers driving different routes. Because of this I am not always so sure that disappointing mileage always means something is wrong with the car.

First, note that the real figure for mpg is zero when the car is stopped at a light, stop sign, behind stalled traffic, or sitting at idle in at take-out line. I rarely drive in town when the driving matches that used in government test here in Canada, so when I spend any more than 4 minutes idling out of 23 minutes of driving, I can’t be too shocked when my mileage is less than the government figures for the smart tested with only 4 minutes of idling out of a 23 minute test. The government, however, does provide fuel saving tips and notes that idling for more than 10 seconds uses more fuel than it takes to restart your engine, advising drivers to turn off the engine if idling more than 10 seconds because it has minimal impact on the starter system. The government’s fuel saving tips material also states that air conditioning can increase fuel consumption by as much as 20%, which would drop 50mpg to 40 mpg, or 40mpg to 32mpg. They even suggest to set the air conditioner at a minimum in order to allow the air conditioner to shut down once the cockpit is cool enough, suggesting that those running the air at maximum are likely to top out the fuel consumption increase via air. So, I would expect that air conditioning use will be different from individual to individual, therefore causing some difficulty in individual to individual comparisons. Not sure I would want to sit out front of a dealership with a protest sign until I checked out my mileage with minimal idling time and minimum running of the air conditioner.

Second, all those other variables influencing mileage are also likely to impact individual to individual comparisons: variables such as hills on the route as well as steepness of hills, speed, acceleration rates and frequency of acceleration vs constant speed, weight being carried, wind or direction of travel, tire pressure, gas quality, etc. As to gas quality, I understand that ethanol added to gas reduces mileage, although I have lost the official reference to this statement and can’t recall exactly how much, but I would suggest that comparisons are best when the fuel is held somewhat constant. Many individuals have made comparisons from fuel sources and found mileage variations due to sources of fuel. As to tire inflation, our government fuel efficiency tips include the statement that for every 4 pounds of under-inflation, fuel use increases by about 2 percent...unfortunately, safety concerns limit how much one can/should inflate tires, so the term “under-inflation” refers only the car/tire specific recommendations. As to speed, the general rule of thumb is that the fuel consumption curve increases rather rapidly at any speed over 60mph, and in Canada the government states that decreasing one’s speed from 120km/h (about 74.6mph) down to 100km/h (about 62.1 mph) can reduce your fuel consumption by up to 20%, which is comparable to driving with the air conditioner on full load...gee, one could cut good mileage by nearly half without much effort at all, eh?

Sorry, but my smart is new and I have yet to have a highway only ride, or a tank consumed under conditions allowing minimal idling times given I have yet to replace idling with engine off conditions. I have four gas receipts showing an average of 5.875 Liters/100 km, which is dead on for the governments rating o

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Permalink Reply by Jim Mottin on July 17, 2008 at 1:19pm

NOT SURE WHAT HAPPENED TO THE ABOVE REPLY, BUT HERE IS THE REMAINDER OF THE SUBMISSION STARTING WITH THE "SORRY ..." PARAGRAPH.

Sorry, but my smart is new and I have yet to have a highway only ride, or a tank consumed under conditions allowing minimal idling times given I have yet to replace idling with engine off conditions. I have four gas receipts showing an average of 5.875 Liters/100 km, which is dead on for the governments rating of the smart...for city driving. Unfortunately, some of those receipts are for driving that included trips 10 miles out of town and back, so it is disappointing. Well, those trips included 12 stops each way, 10 of which were at lights where I can’t recall ever hitting close to green.

Oh yes, the government’s rating for the smart translates into 48mpg city, 59mpg highway, but that is in imperial gallons.(my average of 5.875 above translating into 40.034mpg US gallons). So, if you really wish to impress others, casually fail to mention that your mileage averages are being expressed in imperial gallons. Thus, I am averaging 48.081mpg!!!!, minimal highway, no ethanol, modest speed and acceleration, stock Canadian smart. But it is a fun drive.

Oh yes, since I am driving in Canada I suppose I should mention that it is summer here and far too much of the driving mentioned above has included driving with the air conditioner on far more than I would like, especially when the wife is on board or when carrying a friend. Best estimate, 80% of the mileage was with air set moderately.

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Permalink Reply by Dorenda Truesdale on July 17, 2008 at 5:34pm

I appreciate everyones input. I have decided not to run the air conditioner during this tank. I do alot of short distance driving to work and back and very little on the interstate. I understand that this may be causing some difference, but it didn't affect any other car I drove as drastically. We have also taken it to the dealer and the computer has been reset. I will check the tire pressure next opportunity and keep everyone updated. All in all - even with the lower gas mileage - I LOVE my Smart. Wouldn't trade it, but would like to get gas mileage consistent with everyone else.

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Permalink Reply by niceguy on July 17, 2008 at 7:41pm

Are you in HEAVY traffic?

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Permalink Reply by Dorenda Truesdale on July 17, 2008 at 7:46pm

No - very light, but a very short distance. I only have to drive about 2 miles to work each day.

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Permalink Reply by mr bad example on July 17, 2008 at 8:55pm

i was getting 36-38mpg in 2-6 mile commutes with my metro. second to last job was 6 miles of semi-decent road, 40-45mph, i think i could get 50mpg on this commute with the smart (i suspect 40-45mph is the "sweet spot" for smarts. i'll get a SG2 when i get my next job, sucks to be unemployed, i got a few irons in the fire)

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Permalink Reply by Jim Mottin on July 19, 2008 at 9:18pm

My guess is that part of Dorenda's fuel problem is in fact the short trips. Taking short trips of less than 5K, or 2-3 miles, tends to burn more fuel in all seasons because the engine and drivetrain do not reach their most efficient operating temperatures. It might be worth some comparisons over various lengths of trips on the same car before concluding the car is the problem. It is best to warm a car by driving it, not running it at idle, but most fuel saving tip instructions will suggest that short trips produce the worst mileage, I believe.

Best of luck with the new setting on the computer and I hope your other efforts pay off too.

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Permalink Reply by niceguy on July 19, 2008 at 10:42pm

I am jealous, wow just 2 miles.

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