Gas Mileage and RPM's?

[neliconcept]

I did drive kinda slow and stayed out of the skinny pedal to see if I could make it there and back on a single tank. Traffic was bad and I was in no hurry.

yeah and i might be a little low on pressure in the tires anyways. ill have to do some more driving and do it in the 60-65 range to see what I get next time

[bdg4512]

Man I am doing good to get 260 miles on a tank with all hwy driving. I keep my tires at 38 also.

2200rpm/70mph
no idea what my gearing is

I'm driving home from school tomorrow(read all hwy driving) and I'll take it easy to see what she'll do.

[Bajabwk]

Alright, something must be wrong with my ride. Im running 285's i have a K&N intake im in pretty much getting 15.5 MPG on highway and/or city. Not normal right?

[bamachem]

question though. how do you guys calculate your MPG's..especially for city & highway? i usually take the range/tank, but i never go to empty and never know how much is used/left to make an accurate estimate.

Ok, here ya go:

Fill up your Tank. Reset your Trip Odometer. Drive.

Now, at any point, but preferably after consuming at least 3/4 of a tank (to get a good average), go back to a gas station and fill up again. Make sure to fill up in a similar manner as you did the previous time. That means that if you "topped it off" with an extra gallon last time, then do that again. If you stopped filling when the pump automatically shut off, then do the same this time.

Now, look on the gas pump and see what the volume was that you put in the tank. Now look at the trip odometer and read how many miles you drove.

Ok, now for the math:

Divide the Miles Driven by the number of Gallons that you put in the tank.

In this example, lets say that you drove 280 miles on 14 gallons (makes for some simple math).

So, 280(miles)/14(gal) = 20 MPG

Now, you have to account for your tire size difference.

If you had 31's as original, but now you have 33's, then you have actually traveled farther than your odometer stated. In that case, you divide your current tire size by the original size.

33/31 = 1.0645

This is your "multiplier" that you need to use to correct your MPG's.

So, you then take your calculated MPG and multiply it by this factor to get your actual MPG.

20 MPG X 1.0645 = 21.3 MPG actual

[ecchamberlin]

Andy
good point. I didn't calc my tire size diff when I did my mpg so now it would be

19.56x1.0645=20.82mpg

Makes a difference. Almost 21mpg w/ 115K miles, lifted, 33" tires, lots of extra weight is nothing to complain about at all.

[pdxsteve]

2000 4Runner, stock except for Wild Country TXR (D load)

275/70/R16 Wild Country TXR Load rating D 8-ply

around town can be as low as 16.5 or less with winter gas

last road trip from portland to sisters, oregon was 22.32

122k 3.4L

usually try to run around 2-2500 rpm, up to 3500 at times to pass or up big hills

i can live with this, casue i ride my bike and get to use a company car at work

plus, tires are expensive

[JB_96LTD]

1996 3.4L with just under 150k miles. I have averaged 18.5-19 mpg (mix of city and highway miles). I usually hit 3-3.5k rpm max.

I have stock wheels and tires. The aftermarket mods are OME lift, Jardine catback exhaust, and air intake. I have all Mobil 1 syn fluids as well.

[tulsa_sr5]

If you can double check your speedo/odometer with a GPS that's the best way to figure out the true adjustment. The speedo/odo will generally be off in a few % to start with, and actual tires sizes are generally off too, ie 33" tires that are closer to 32.5" The differences here may not add up to a whole lot.

[SteveO]

The vehicle: 1999 4Runner Limited w/4spd Auto 4x4 w/Tow package
Given the constants:
Speed: 70MPH
Transmission Ratio: .71 (Overdrive)
Transfer case ratio: 1

Stock
Axle Ratio: 4.30
Tire Diameter: P265/70R16 (30.6x10.4x16)
RPM = 2343.6

Modified to crawler status
Axle Ratio: 4.88
Tire Diameter: 37" MT/R
RPM = 2202.5

Modified to commuter status
Axle Ratio: 4.88
Tire Diameter: 35" BFG/AT
RPM = 2328.3


When I'm driving conseratively (60mph), I can get 19mpg in town/hwy, and 20-21mpg on the hwy.

[DoubleZero4x4]

Well, since someone asked, I will post my #'s as well.

2000 SR5 4x4 Auto Trans, Stock Rear End

2 adult passengers, loaded with camping gear, tent, clothes, and 2 bikes in a bike rack on the hitch (about 110 lbs). - Driving from Gilbert, AZ to Oshkosh, WI, so it was 100% highway.

Miles Cost Gallons MPG MPH Driving Conditions
166 $25.00 8.449 19.65 55 Mostly mountain to Winslow AZ
261 $40.00 13.337 19.57 80 Mostly Flat highway to Albq, NM
263 $37.00 12.462 21.10 75 Flat highway to Amarillo, TX
263 $39.01 13.730 19.16 75 Flat highway to Oklahoma City, OK
262 $39.00 14.134 18.54 70 Flat highway to Springfield, MO
197 $30.00 10.070 19.56 70 Mostly Flat highway to West St. Louis, MO
267 $43.00 13.875 19.24 70 Flat highway to Rochelle, IL

These are real numbers as we have a laptop mount in the truck and track our speeds and mileage via moving map GPS and a spreadsheet that I put together. We can even playback part or all of the trip with the map software. The trip out there was 27 hours 35 minutes drive time. For those wondering yes it is straight through.