Gas Mileage and RPM's?

[bamachem]

I thought it would be good to have a thread with observed Gas Mileage, along with your observed RPM's at different speeds, as well as tire size, gear ratio, performance mods, etc, for other's to compare to.

I drove the runner to work the last two days.

At an indicated 55MPH, my actual was calculated to be approx 60MPH, and my indicated RPM's were 1700. At an indicated 68 MPH, my actual speed was calculated at 75 MPH, and my RPM's were 2200.

I had approx 160 miles of interstate driving with some hills at a steady indicated 68 MPH (no cruise set), and then another 78 miles of back-roads and city streets, some very hilly and curvy, causing lots of acceleration, braking, etc. I got ~16.7 MPG on this last tank! That's with 315/75-16 tires as well.

:D

Tires: 315/75-16
Gears: 4.56
Performance Mods: None
RPM's at 60: 1700
RPM's at 75: 2200
MPG: 16.7 (2/3 highway mix, with hills)

[p nut]

For those with bigger tire sizes, I would think that it would be very helpful if the MPG with stock tires were posted at the same time to get a good baseline and comparison of what we're working with.

For me, I'm 100% stock right now, and these are my stats so far:

Date Miles Gallons MPG PPG Highway / City (percentage)
5/8/07 306.3 14.716 20.81 $2.929 90/10
5/10/07 184.6 8.168 22.60 $3.019 90/10
5/14/07 201 10.636 18.90 $3.069 20/75
5/16/07 224 10.432 21.47 $3.059 70/30
5/21/07 193 9.866 19.56 $3.059 80/20
5/23/07 180.8 8.512 21.24 $3.079 90/10
5/29/07 151.4 8.057 18.79 $3.119 40/60
6/1/07 294.5 12.837 22.94 $3.199 80/20

I noticed that since the winter gas has been phased out, my mileage has been getting better. Most of my driving is on the highway between 70-75mph (with a few stints at 80mph). No stop and go traffic, usually. Pretty level, except for a few hills. Cruise is on whenever possible, which is about half the time.

I will report back when I upgrade to a bigger tire size later on in the future.

[d0ubledown]

wow...my mileage absolutely sucks arse. theres gotta be something goin on. im guessing that since 99% of my driving is city...im getting very poor mileage. but i should be getting more. my buddy with the same runner, but on 33's and stock 4.30's is getting 350KM average/tank compared to my 280-300. not surprisingly, when i do highway driving like coming back from camping or wheeling...i get more km's/tank.
motor: 3.4L V6
tires: 315/75/16
gears: 4.88
performance mods: non. but many non performance mods like big tires & heavy bumper.
rpm @ indicated 60: 2200
rpm @ indicated 75: not sure. havent taken it that far yet.
KM's per tank: approx 280-325..YIKES!

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.

[sacedrunner]

i have 4.88s and 35s and a 2.7l auto. i fill the tank 60 litres and i get about 400-500 km's to a tank at 2000-2500 rpms and thats right empty. and my speedo is right on to

[neliconcept]

Ive noticed on highway speeds it wants to jump up to 4k every so often because it cant maintain 4th gear a lot.

285s
3.4L
4:10 stock gear
i think i around 2200 rpms around 70mph

I'll get a correct estimate tomorrow as I have to get back on the highway to pick up my girl.

[Henry]

I'm pretty much stock. On highways its about 2200 - 2500 doing 75-80 getting 17-18 mpg. Unfortunately I do mostly short, stop and go, hilly city driving getting like 11 mpg. Torture filing up an empty tank on nearly all city driving.

[Seanz0rz]

i try to keep it always under 2k rpm, and im getting up to 18mpg with the mods in the sig.

adjusted for tire size, 65 is reached at about 1900 rpm. and i never exceed 70 mph, always try to keep it 65 or 60 on the freeway, takes a bit longer to get there.

[ecchamberlin]

I just did an almost entirely Hwy tank of gas to go up to Bruces place to get my new rear bumper. Rare for me now that it is not daily driven. Thank goodness.

285's/ 70mph / 2200RPM / 313miles on 16 gallons =19.56mpg /4.10 gearing

I keep my tires at 38psi on the road.

I was pretty happy with this milage.

[neliconcept]

I just did an almost entirely Hwy tank of gas to go up to Bruces place to get my new rear bumper. Rare for me now that it is not daily driven. Thank goodness.

285's/ 70mph / 2200RPM / 313miles on 16 gallons =19.56mpg /4.10 gearing

I keep my tires at 38psi on the road.

I was pretty happy with this milage.


very nice

i was actually pushing the same rpms just a while ago on the interstate.

as far as gas mileage goes im pushing like 260 a tank (non calculated) but still thats about 17mpg anyways.

[ecchamberlin]

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.

[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.

[surf4runner]

02 sport 2wd 275/70-16
usually 2200 rpm @ 72 mph yields ~20 mpg avg

just did a 2000+ mi trip to OR (mostly on cruise control)
2600 rpm @ 83 mph = avg 20.6mpg (3 diff full tank stretchs)

180 mi @ 100mph dropped it to ~17

[tulsa_sr5]

Found a nice link for calculating different tire sizes and the % your speedo/odo may be off. GPS is still better of course.

http://www.miata.net/garage/tirecalc.html

[MTL_4runner]

Just did a family trip (3+ hr each way) this weekend and I found that 2250 RPM (via tach needle) = 70 MPH. My tires were at 35 psi hot (ie checked them at the gas station after driving 1 hr). I only use regular gas (87 octane) in my truck.

My trip up and around town (about 75% highway and 25% city, some cross/head wind and sunny):
214.5 miles and it took 39.55 liters (10.45 gal) = 20.5 MPG

My trip back (100% highway, no wind but raining fairly heavy):
165.6 miles and it took 27.39 liters (7.24 gal) = 22.85 MPG

I'm pretty sure I would have averaged over 23 MPG had it not been raining so badly (highway was rutted and you could feel the resistance when the tires hit the puddled water). Also the highway is mostly rolling hills with very few flat sections so it might even go as high as 23.5-24 MPG if the roads were flatter like out west. I don't think I could squeeze any more MPG out of this truck than I'm getting now without turning it into a hybrid. :D

[MTL_4runner]

Just did another check with mostly city driving (aka grocery getting) and still came out pretty good.

124.0 miles and it took 26.92 liters (7.10 gal) = 17.5 MPG

Either I'm getting great gas this year or the synthetic oil has really been helping my fuel economy.

[flykrs1]

Here are my numbers from part of a recent trip.

2000 3.4L
265/70R16
TRD Exhaust & Headers
Deckplate OEM filter

2k RPM at 65 (4.10)
32psi cold

258.2 miles @ 70-75 = 20.2mpg
283.1 miles @ 70-75 = 21.3mpg

driving @ 65 I can get 400 miles out of 18 gallons

city driving guestimate is about 16-17mpg

all of this on 87 octane

[xcmountain80]

Im using 3 different setups now consider I almost always drive as fast as I need to go 70mph or less sometimes 80 but not often.
2002 3.4L auto 4.10
#1 285/75/16 Cooper STT's + roof tent = 15-16mpg
#2 285/75/16 Cooper STT's = 17mpg
#3 295/75/16 Nitto TerraGrapplers = 17mpg

Aaron

[MTL_4runner]

Yet another grocery getter MPG check:

242.1 miles and it took 51.67 liters (13.63 gal) = 17.8 MPG

Still very impressed by the synthetic oil's effect on my fuel economy.

[MTL_4runner]

Yet another MPG check:

231.7 miles and it took 53.54 liters (14.13 gal) = 16.4 MPG

Mileage did drop, but not sure if that's because of more stop and go or that it's been really hot this week.

[ecchamberlin]

Are you running your A/C? I know that has a noticable effect on my MPG.

[MTL_4runner]

Are you running your A/C? I know that has a noticable effect on my MPG.


Good point, yes, it was running pretty much on full blast the entire time because it was so hot. The prior weeks it had not been running more than sporadically on low. Sounds like that is mystery solved....evidently the AC will cost you just over 1 MPG running it on full.

[garrett]

Do the different levels actually affect gas mileage? I thought the A/C is either on or off... and it's just the fan speed you control. I'm probably wrong though.

[mastacox]

If the A/C works the way it's supposed to, the compressor should cycle on/off as needed. So less air blowing = less air to cool = less compressed refrigerant needed.

[MTL_4runner]

Do the different levels actually affect gas mileage?
I thought the A/C is either on or off... and it's just the fan speed you control. I'm probably wrong though.


Yes, the AC is on or off but it cycles on / off depending on the fan setting. If you have the fan on low, the AC cycles on and off via the compressor clutch, but might only be on 25% of the total time. If you have the fan on full blast, the AC doesn't really cycle at all and the compressor clutch will be engaged 100% of the time. So to answer your question, yes, it would make a difference. Try it and you'll see how much the compressor clicks on / off (watch how long the compressor spins for vs the time it is not spinning) depending on each fan setting.

[ecchamberlin]

very interesting I never thought about it really. Make perfect sense though.

I saw a myth busters about a/c vs. rolling the windows down and they clearly showed that the a/c was more efficient than rolling the windows down at hwy speeds.

[garrett]

I saw a myth busters about a/c vs. rolling the windows down and they clearly showed that the a/c was more efficient than rolling the windows down at hwy speeds.


makes you wonder if it stands true with out super aerodynamic roll-down rear window, doesn't it? :smokin: :king:

[xonetruthcrewx]

Gearing: 4.88
Tires: 285/75/16
Performance: Cat back exhaust and Airaid Jr. Intake
RPM's @ 60mph: 2100
RPM's @ 70mph: 2475

Average MPG is right around 13. Thats pretty much city driving. Straight freeway driving i will pull around 16. I always drive with the ECT on and i kinda have a heavy foot. I'm sure that the extra 600ish lbs of crap on/in the rig at all times dosent help either. Oh well, gas prices are going down. Only 3.20 a gallon now. Haha.

[xcmountain80]

D

Gearing: 4.88
Tires: 285/75/16
Performance: Cat back exhaust and Airaid Jr. Intake
RPM's @ 60mph: 2100
RPM's @ 70mph: 2475

Average MPG is right around 13. Thats pretty much city driving. Straight freeway driving i will pull around 16. I always drive with the ECT on and i kinda have a heavy foot. I'm sure that the extra 600ish lbs of crap on/in the rig at all times dosent help either. Oh well, gas prices are going down. Only 3.20 a gallon now. Haha.


Dang well 4.88's are out for me I'll stick with wondering whether the 4.56's would be better. You might get better mileage running 35's on your rig!

Aaron

[xonetruthcrewx]

Yeah, it sucks, but oh well. As soon as my current tires wear out i will be running 34's. Maybe i will bump my mpg up to 14. Haha.

[xcmountain80]

Yeah if you go with 35's you might get a little more. I know Austin (my brother) runs the 4.88's on his Taco DC and he swears the mileage didn't change much. In disbelief I grabbed my gps and we went for a ride. His RPM's were in a pretty normal range with the stock gearing and tires.

AAron

[xonetruthcrewx]

Maybe, but 35's are too much, especially for the way i drive. When im really rompin i have rubbed the 33's. I have done a little trimming since and im pretty sure 34's will be perfect. 305/70/17. A 315 is too wide for the 7.5" wide FJ rims i have anyways.