How Wisebread helped me get 45mpg out of my 28mpg car.

by Paul Michael on 23 May 2008 16 comments
Photo: sonnysideup

There have been several great articles written by my fellow Wisebread writers on gas efficient driving , slowing down and hypermiling . I think the sign of a good blog is that we take our own advice, and in the case of gasoline, I’ll take all the help I can get. But even I was shocked at the amazing results I got.

Before I took the advice, the best I got out of my 2006 VW Passat was 31.8 mpg. And I was happy with that. As you can see from the image below, the top mpg for my vehicle is 28mpg highway, and a paltry 19mpg city. So, I felt good about myself.

vw passat

But as it turned out, I had a lot of bad driving habits. For a start, I was guilty of a lead foot, slamming it down as soon as the lights turned green. I would drive at the speed limit or just above, which meant doing 70mph when I was allowed. And I would often drive a little too close to the car in front. Not dangerously so, but enough to make me have to stop more quickly at a red light.

With all of this going on, I was still a pretty good driver. Getting my 31.8 mpg was nice to see (I have one of those mpg monitors in my display, which is very handy). But, I wanted to see if I could squeeze a little more out of my car using the tips from Lynn and David .

Here’s what I did:

First, I slowed down. I found 55-60mph was all I needed to do. Sure, it sometimes added a little more time to my journey, but only a few minutes. On my morning commute, I set off a little earlier.

I left much more space between my car and the car in front. This allowed my to coast more, and I did a lot less braking. Sometimes I would find myself never stopping, but merely slowing and speeding up. And remember, when you stop at a light you’re getting a big fat ZERO mpg.

I stopped treating traffic lights like the beginning of a Nascar race. Instead, when the light turned green I pulled away slow and steady. Sometimes I’d hear honking horns but I just ignored them. So what?

I used my cruise control. This is one of those hypermiling tips that is killer. Unlike the accelerator peddle, the cruise control + and – settings are much more accurate and controllable. I could accelerate by 1/2mph or 1mph, and slow down in the same way. This is very gas efficient.

That was it. I started a few months ago, and this week I hit 45mpg on a trip that I used to get 29mpg on. The proof is below. It’s not the best quality, it was taken on my cell phone, but it’s not tampered with in any way. Scout’s honor.

pauls car

What does that mean monetarily? Well, my car has an 18.5gallon tank. It costs around $65 to fill it up (and who knows how much more that will increase to…scary thought).

Using my old method of driving, the most mileage I can get from that tank (if I’m only taking highway journeys) is 588 miles. That’s 31.8 x 18.5. Now, with my new method of driving I can get 832 miles from that one tank of gas. That’s 244 extra miles, or about 5 gallons of fuel. That’s a bunch! And I’m filling my car up every two weeks, which means Wisebread has saved me up to $40 each month. And by the way, I don't do a lot of city driving, but when I do I still get 34mpg. That's almost double the estimate for my vehicle. 

It just goes to show…it pays to listen to your friends sometimes. Thanks Lynn and David.

4
Average: 4 (4 votes)
Your rating: None
ShareThis

comments

16 discussions

Add New Comment

CAPTCHA
This test helps prevent automated spam submissions.
Guest's picture
sd

though not as extreme. I just filled up for the first time since implementing some of these ideas (particularly throwing the car into neutral and coasting toward lights). My max for a while was around 21mpg. today it came out to 26. sweet.

Guest's picture
Guest

When you take forever to go at the green light, the drivers behind you have to stall longer and end up getting stuck on two red lights at the same intersection. That wastes fuel too. You don't need to be a NASCAR driver to get your butt in gear when the light turns green.

Guest's picture
Sean

I thought I was doing decent, similar to your "before" results. But I can probably do more cruise control on a regular route. Looking forward to it next week.

Guest's picture

you won't get hit by any red light runners. I am always amazed at how people accelerate right thru the light...when it first turns green. I bet no one ever got hit at a red light who, after the light turns green, looked left, right, left again and then went on their way....and no, this only takes a split second to do (along with gently accelerating).

Guest's picture
Christopher Smith

I can't scrounge up the source at the moment, but I've seen credible evidence that accelerating quickly and smoothly doesn't harm gas mileage and may actually improve it; remember, your engine is much more efficient at 45mph (or whatever the street speed is) than at 25mph.

The conventional-wisdom view that accelerating quickly is inefficient comes from conflating quick starts with frequent starts and stops. In particular, if you're in an area where you have lots of unsynchronized lights or stop signs, then starting quickly costs you gas--but from speeding all the way up and then dissipating the energy by braking, not from the speeding up itself.

In short, then, it seems that if you're in a situation where you're expecting to be able to drive for a while at full speed (either no light for a while or synchronized lights), it's both faster and more efficient to accelerate quickly without slamming on the gas.

Guest's picture
Guest

it's true. Riding the 'torque curve' is the key. That means accelerating smoothly and efficiently from a stop to the most efficient speed as quickly as possible.

the sweet spot for a gasoline engine is around 2520 rpms. That's where the rpms achieve maximum torque with minimum fuel consumption.

Guest's picture
Jim

When I saw this article, it was a pleasant surprise because, sure enough, this is where I first heard about "hypermiling." Driving an '03 Corolla, I resisted trying the practice out until about a month ago when prices really started getting ridiculous. Personally, I went from about 32 MPG to 40. This is my city/hwy record per-tank average, as I don't have some fancy instrument that I probably wouldn't trust, anyway. Nonetheless, 25% is huge! What if every American did this? Our demand would go down and hopefully liberate prices a little. Living on the MA-NH border, I'm noticing that only some New-Englanders get peeved when I accelerate a little more slowly. Reasonably slowly, not "I don't care about any of you" slowly. Surprisingly, it's contagious. Other people start to notice and drive more sensibly, usually widening their following distances before trying anything else. Others immediately gun it and pass me on a two lane road out of an intersection, only to find that I nearly always catch up to them and occasionally even pass them later! Ahh, instant gratification - it's the American way.

My experience with cruise is not so great. Toyota cruise controls tend to shift quickly and gun it on hills - I've fared much better by taking matters into my own hands... or feet. I've yet to try acceleration by cruise control - I have to admit that it seems a bit extreme. Bostonians get really ticked off when you try something like that, and I never would have survived if I'd tried that around New York. It's "gun it or be gunned down" there.

Guest's picture

I've been hypermiling through my last tank of gas, and even though I botched my fill-up on my Scan Gauge II AGAIN, I was able to manually calculate my current mpgs to 29.83 over the life of my last tank. My car is a Accord V6 with EPA estimate of 18/26 (21 avg). To best my mileage by 8 average MPG (my commute is about 80/20 city/highway, so I'm really beating 19MPG most of the time) is well worth the effort I put toward the goal.

I travel in off-hours, drive with load, and coast as much as possible. Cruise control is OK, but it's not as good as knowing what your throttle-position sensor and ignition timing read. Throwing up fuel consumption/hr predictions also help one determine how much gas to give the car.

Guest's picture
C

I'm glad to hear these tips really work - I've been using some of the same ideas, but don't have a handy mpg counter in my Toyota.

Guest's picture

I have been doing the same as well and it makes a great difference. Not only do you save on gas buy driving a little slower and not taking off at a stoplight, you are prolonguing the life of your car.

Great tips to save on gasoline:

High Price of Gasoline

Linsey Knerl's picture

The vehicle I drive most doesn't come with one. Any ideas for a stand-alone solution?  (I was looking at the ScanGuage II anyway, because I needed a reliable code reader.)

Guest's picture
Lucillel

I have an older Passat 1.4 turbo. I have two options for getting to where everything is. Two lane highway with stop signs or interstate. I had been taking the interstate but you HAVE TO drive between 65-75 or you will get run off the road or run down by an angry semi driver. So this means your accelerating, passing or moving quite a bit. I am starting to think those interstate drives during rush hour may be wasting more gas than the start stops on the road that has a 60mph limit and less of a NASCAR situation.

I may make some actual MPG calculations and see what route really does use less gas. I also noticed I get better gas mileage after the car is warmed up.

Guest's picture

Thanks for this...it gives me a little more impetus toward trying out the various "hypermiling" techniques. After the $56 fill-up a couple days ago, I decided to try these, but...

In my area, the traffic lights are synchronized. If you coast instead of braking to slow down, you quickly get out of synch, so you end up stopping at every single g.d. red light. They seem to be set at about 5 mph over the speed limit, so if you trot along at 45 mph in a 40 mph zone, you can go for mile on mile on mile without ever stopping. But if you ease off the gas (rather than braking fairly quickly and getting back up to the 45 mph speed quickly), you'll be stopped at every light.

I haven't tried the cruise control because I've always thought it was unsafe to use on the surface streets and on crowded slow/stop/speed-up urban freeways. But maybe this weekend when traffic is minimal, I'll try that out.

Guest's picture
wildgift

You can write the amount of gas you buy, and the odometer reading every time you fill up - and you should fill to the top each time. Over time, over time, you'll be able to calculate an average mpg. The formula is: (today's odom reading - previous reading) / today's fill up amount.

That's your miles-per-gallon.

Do this a few times and take an average.

Another way to do it is to take a lot of readings, and take the total miles driven, and divide by the total amount of gas bought. Start measuring at a full tank, (or fill up and discard the first reading), and include the final fill-up amount. With this method, you don't need to fill up each time, just at the start and at the end.

If you don't like to do the math, you can use a spreadsheet. Searching for "gas mileage spreadsheet" turns up a lot of pages.

Guest's picture
culture.detox

I have a turbo sports sedan (subaru WRX) and the stock MPG is 21/26. add to the fact that I have to use premium, and filling up really starts to hurt.

what I've done is pump up the tires (but not too much to affect brake distance and water traction) to about 43front /40rear psi.

I Have an ECU reflasher that changes the mapping of the Car's computer. I first used it to get more HP out of the stock motor. but I switched it to the econ map. which pretty much "turns off" the turbo and leans out the AFR, and my exhust has a hightflow cat, thus making the engine a bit more efficient than stock.

To get the most out of the gas when accelerating, I find that I need to get to my target speed as efficiently as possible and then coast at the tallest gear possible. I accelerate it firmly, (not stabbing with the gas, but accelerate linearly) short shift before 4k (as fast as I can up to the speed I need.

I keep the rpm's under 4k at all times, this keeps the car out of the closed loop /open loop transition that can really suck up the gas (I think this is a subaru only thing, I'm not familiar with other makes and their how their ECUs work).

so far this has netted me 32mpg around town and 36 on the highway. I'm pretty much maxing out the best I can do right now before moving to more extreme measures to improve milage; such as putting on low-rolling restience tires that are skinnier than stock, smoothing out the air turblence under the car with a few aerodynamic bits, taking off the box spoiler wing and mudflaps, putting on some slimmer mirrors and some moon hubcaps to net some more mpg. Thats a bit too extreme right now but not out of reach in the future.

Guest's picture
MN

I drive an '05 buick rainier, the guage cluster info center was telling me that the previous driver was getting an average of 13.7 mpg, combined city and highway, then I reset the guage, and because of simple hypermiling, and oil change, and transfer case oil change, reinflated tires, and the slow and steady pace plus gut wrenching exit ramps (50 mph was my fastest and scariest cloverleaf, coming off of the highway), I have had my fuel economy peak at 27 mpg, in an awd, heavy, cumbersome, v6, SUV, only issue, town driving, 30 mph, is 25 less than ultimate....
one other thing, hypermiling even works on crotch rockets, I had to fill my tank 3 times to get to drive 134 mi, after, I could do the whole thing on 5 gallons, 12 bucks for a 134 mi commute is pretty nice...