MPG Pt.1

[Skunksmash]

Another thing that most people don't consider, which has a very dramatic effect on gas mileage, is aerodynamics. These trucks are about as aerodynamic as a brick sailing through the wind. Put it this way, at 60Mph, the average car uses HALF its fuel fighting the air resistance. Think of how much better mileage that car would get, if it could save half its fuel at 60Mph. That's how big the effect of aerodynamics is. You should see the awful, awful things they're doing to cars over at the ecomodding forum. They look hideous, but they see a big jump in MPG. I'm certainly not willing to go that far. The most I would do, is maybe come up with some of those covers that cover up half of the rear wheel, like some of those old cars used to have.

But not on my truck lol. Only on my toyota Yaris which already gets 35 MPG city.

[Stewart G Griffin]

281.7 miles, 16.73 gallons = 16.83 mpg

$56.22 to fillup @ 3.359 a gallon  Exxon.

i'm baffled why there is a 1mpg difference between this time and last.

2) i agree with aerodynamics.  i'm a little short on time right now, so any further experimenting will have to be put on hold.

[Skunksmash]

Another thing you might try are those MPG helper things. Forgot what they're called but I'm sure you've seen one at some point. They help you change your style of driving. Its just a little screen that you mount somewhere and plug into... something. The wife's volvo S-80 had one built in from the factory. Tells you exactly how many MPG you are getting at any given time, or you can look at your average. I started using that thing and was able to see a 2 MPG increase. Mainly just because I stopped accelerating much to stop lights, and coasting down hills. Applying the brakes as little as possible. Stuff like that. The little readout starts showing your mileage going down the toilet when you accelerate and it makes you drive better.

A lot of those overpriced programmers have them built in these days, such as those "Bullydog" products and the like. Although, you can get just the gauge for much less.

[Stewart G Griffin]

i have a link to one of those computers that i can dig up maybe later.


But i think the most basic thing which i don't think has been mentioned here is tire air pressure.   i think a weekly check is reasonable.  Although monthly could work also.

[velojym]

Depending on whether your truck has OBD. The old-school method is to use a vacuum gauge so you could see what sort of engine load you have. They were (are?) sold as economy gauges, and work on older vehicles with carburetors.

[Jason S]

I don't know if this helps anyone, but I'll throw this in the mix...

My Dad had a '87 GMC R1500 350, 700R4 (don't know what rearend ratio) that he would usually get 20 mpg. 

Additionally; while driving the straight, flat highways on the high plains, his '96 GMC C2500 350, 4L80, 3.73 would 20 mpg. 

However, I rarely get over 14 mpg in my 2005 Chevy 2500, 4x4, NV4500 with 4.10's... And I've never got better than 12 mpg in either of my '70's GM trucks.

[Skunksmash]

But i think the most basic thing which i don't think has been mentioned here is tire air pressure.

I have been studying up over at the ecomodding forum. Its pretty common for those guys over there to overinflate their tires by about 5 psi. They say it gives you a small boost, while not really hurting the tire. They say that the old bias ply tires were the ones that were more prone to wearing funny when overinflated. Plus only going 5 PSI over doesn't do much harm anyway. But you gain a small percentage of MPG. Might be something I try out sometime.

I don't know if this helps anyone, but I'll throw this in the mix...

My Dad had a '87 GMC R1500 350, 700R4 (don't know what rearend ratio) that he would usually get 20 mpg. 

Additionally; while driving the straight, flat highways on the high plains, his '96 GMC C2500 350, 4L80, 3.73 would 20 mpg. 

However, I rarely get over 14 mpg in my 2005 Chevy 2500, 4x4, NV4500 with 4.10's... And I've never got better than 12 mpg in either of my '70's GM trucks.

I've heard a lot over the years about the TBI trucks being able to get 20 MPG if you do the right stuff. One of the things that some people do to them is raising up the throttle body. Some guy came into the tire shop I worked at as a teen, and he had some kind of weird looking, double throttle body spacer setup. He said his truck often got 22 MPG. Had some kind of weird looking open intake thing going on too. Now that I have one of the trucks I wish I knew who he was.

[Captkaos]

Before the transmission went out on my 87, it always got 17/22 and it was completely stock, around town it was getting 20mpg.

[Stewart G Griffin]

244.9 miles,  16.7 gallons  = 14.66 mpg   mostly highway miles.

$64 at exxon to fillup.   i think sign price was $3.81   The reciept didn't print out fully.

i may start a part 2 as i want to get into aerodynamics but i can't promise anything.

[Stewart G Griffin]

265.5 miles,  17.538 gallons = 15.13 mpg

$3.639 per gallon at BP

$63.82 total to fill up.

P.S. i've had to take my tonneau cover off temporarily for hauling reasons if that makes a difference.

[Stewart G Griffin]

Wow.  It's hard for me to believe the thread is almost 5 yrs old.  i really need to get on it.


One thing we can see is that the price of gas hasn't really moved that much in that time.   Gas around this time in 08 was over $4.

[Stewart G Griffin]

278.6 miles,  17.411 gallons = 16.00 mpg

$3.479 per gallon   $60.57 to fillup at mobil.

[Stewart G Griffin]

274.2 miles   16.856 gallons = 16.27 mpg

$3.399 at sunoco,    $57.29 to fillup

Mostly highway, some flat bar towing--the cavalier (2500 lbs.) and hauling lumber.   Had the tonneau cover off the whole time.

Still much cheaper than buying a new silverado.

[Steve341]

1975 chevy Scottsdale camper special 454 3 speed auto. 8 mpg lol

[hondarider188]

how are you getting 15-16mpg? i wasnt able to get better that 8.5mpg with the edelbrock i had on and since i put on a Q-jet but havnt gone through a couple tanks yet to confirm my average mpg but the last tank i got only around 10mpg.