Personal experience: driving habits effect on fuel economy

[jtexas]

Thought this was interesting enough to share.<br /><br />I've had my 98 Explorer Sport V6 SOHC for nearly two years. Most of my driving is in town. First year & a half or so I was getting maybe 16, at most 17 MPG. Few months ago what with the price of gas and the wife getting a couple speeding tickets, I've been making a conscious effort to stay within the speed limit. The biggest difference that makes in my daily drive is doing 40 instead of the 55 to 60 I used to do along with the rest of the traffic on a long stretch of parkway. [For the locals, it's Trinity Blvd. from Greenbelt all the way to Hwy 360 - an occasional speed trap.] Interstate driving I rarely drove over 65 or 70 anyway. I can't think of anything else I'm doing differently.<br /><br />My last few tanks I've been getting 21 MPG - I've checked my math several times & that's it. Improvement of up to 30%. Can that possibly be right? <br /><br />Drive time increase negligible - only downside seems to be an increase in the number of tailgaters.

 

[ColdFire]

Re: Personal experience: driving habits effect on fuel economy

Sounds about right, I have the same exploder and that is right about the milage that I get when driving... now when the wife is driving she will be in the 17MPG range but she drives the car a lot harder than I do.

 

[BillP]

Re: Personal experience: driving habits effect on fuel economy

That can be right. One of my cars has an "instant mpg" gauge that tells you what is happening as you drive. Its different from the one that gives avg mpg. I watch the instant gauge and the differences are big around town. I've even found that this car gets higher mpg at 75mph than 70. I guess aerodynamics are cleaner at 75.

 

[KM2]

Re: Personal experience: driving habits effect on fuel economy

wind resistance increases exponentially with speed, so I have read that a 10 mpg increase in speed will double your wind resistance. <br /><br />Most vehicles get the best economy in the 40-45 mph range. This makes a lot of sense as most vehicles will have just shifted into overdrive.

 

[Pony]

Re: Personal experience: driving habits effect on fuel economy

I think shift points and the tranny play a key role........Every vehicle is gonna be different. My truck runs the same RPMs at 40mph as it does 70mph (roughly 2000rpm) 75 gets me to 2500. The air resistance goes up......but I'm not driving as long, so that has to become a factor. I personaly have found that I get better mileage going 65-70 than 40, but thats just my vehicle. I guess we all have to just do our own expiraments.<br />

 

[ndemge]

Re: Personal experience: driving habits effect on fuel economy

PONY, assuming you have a diesel<br /><br />...on my gasser, 460... you shift into 4th gear at 35mph.... so that would be the best speed for fuel consumption. So man does it suck down the fuel going 75

 

[Silvertip]

Re: Personal experience: driving habits effect on fuel economy

Just curious, but how does an engine runs the same RPM at 70 as it does at 40. It isn't possible. If it is indeed a diesel, they don't have nearly the RPM band a gas engine but still, whatever the RPM is at 35 MPH in any given gear it has to be double that 70. Its simple physics at work. The key to fuel mileage is to keep your left foot off the brake pedal if you have an automatic tranny and you brake with your left foot. When leaving a stop light, ease into the throttle -- don't stab it. The gas pedal is a linear device -- not an on/off switch. Especially when towing, anticipate a hill. Gather speed going downhill so you have some momentum for the climb. If you still have a carbureted engine, ease off the gas when approaching a stop rather than just quickly lifting off the gas. If you use cruise control, help it when approaching a hill. Otherwise it takes a second or two for the cruise to realize the speed is dropping. It then must add pedal pressure to make up for the lost speed. Again, its an anticipation approach to driving in hilly country.

 

[Silvertip]

Re: Personal experience: driving habits effect on fuel economy

To avoid a rash of rebutals, Note that I said "in any given gear"!

 

[beezee28]

Re: Personal experience: driving habits effect on fuel economy

Billp<br />Would like to know what kind of vehicle is that? Is it a pickup or a car?

 

[Pony]

Re: Personal experience: driving habits effect on fuel economy

Ya know Upinsmoke.....after thinking about the numbers I posted I didnt think they made much sense either......so this evening when driving around I tried making note of what rpms I was at and where. <br /><br />I think I still had my foot a little in the pedal when I thought I was getting 2000 rpm at 40mph. I think my shift into od must happen right around there cuz if I take my foot off the pedal and "cruise" at 40mph I see 1200 rpm. So now my numbers make more sense at least to me. I was simply looking down as I got to 40 before ans saw 2000 not thinking about the fact I was shifing into od about that time. I am seeing 2000 at 70 and about 2400 at 75. I still think I see better mileage in the 60-70 range......BUT that may be because when I am going in the 40mph range, I am on routes with more stop signs and lights. <br /><br />For the record its gas......

 

[SwampNut]

Re: Personal experience: driving habits effect on fuel economy

It makes a huge difference in my truck too. I can get to nearly 25 MPG if I keep it to 65. I lose a couple MPG at my usual 75 in the city areas, and another at 85 in the country.<br /><br />While towing I can get 11 at 65, and 9 or slightly less at 80.

 

[BillP]

Re: Personal experience: driving habits effect on fuel economy

Breeze28, The instant mpg is on a 1990 Towncar...last yr of the 5.0L in tcars. Sometime before 97 they did away with the instant mpg and kept the avg mpg. It's a good way to see how hard the engine is working. When the tranny shifts into OD at 40 mph the gas mpg increases almost double. Gas mpg changes drastically for the worse in windy weather that buffets the car. Following a semi at 70mph increases mpg another 8-10mpg. Even a car way ahead of you at 70mph in calm winds will punch a hole in the air that gives another 3-4 mpg. Towing in OD scrubs 5mpg at 70mph and the OD isn't down shifting yet.

 

[tommays]

Re: Personal experience: driving habits effect on fuel economy

Around town i find the tack is my friend its just to easy to punch up more RPM than you really need <br /><br />Keeping it below 2200 rpm really keeps my town millage much better<br /><br /><br />tommays

 

[DJ]

Re: Personal experience: driving habits effect on fuel economy

Here's a NEWS FLASH.<br /><br />Did you ever read the EPA test data? Of course not.<br /><br />EPA mileage is calculated at a max. of 45 MPH. with a fully warmed engine. Duh, no wonder nobody meets it.

 

[tommays]

Re: Personal experience: driving habits effect on fuel economy

My truck 2003 is rated at 17/21 and thats what i get <br /><br />My wifes 2005 only makes it highway rateing and falls WAY short on its city driveing<br /><br /><br />tommays