The weird thing is I'm getting around 15.2 mpg whether I'm going to work or out on the highway. I do find it hard to keep the X under 80mph when on the hwy because it's so smooth but the last time I drove down to Temecula I was mostly going 65. The next pure hwy miles that I do I'm going to concentrate on just cruising.

As far as PSI goes the tire max is listed as 44, and my friends all say to run the max if you're doing pure hwy driving if you don't mind the harshness.

Tire rating is one thing, vehicle specs are another. Since same tire can fit many other vehicles pressures will vary. Heavier vehicles will need higher pressure than lighter vehicles.

The Xterra does not weigh all that much comapred to full size trucks out there.

What you should look at is the plackard found inside of the glove compartment that states the proper tire pressure. I believe it states something along the lines of 28 lbs. or so.

Running too high of a pressure (42 is way high) will result in uneven and premature tire wear. Your tires will start to wear on the inside mostly instead of even wear. Traction is also sacrificed and chances of hydroplaning are higher if the tires are overinflated (or underinflated for that matter).

If you do mostly highway then it's o.k. to set the pressure a little bit above the rating indicated on the plackard but not by much.

When I was running stock tires I found out that around 30 psi in the front and about 29 or so in the rear worked quite well.

If you have time the best way to test the ultimate pressure is the chalk test. You apply chalk to section of the tire drive a few feet over a dark surface like a freshly coated asphalt. By looking at the tire and the mark on the ground you can see the contact patch and that way you can determine whether the pressure is too high or too low. Talk to TJ on here on more details regarding the mentioned test.

Thanks for the tire tutorial. 28 is definitely too low from reading the posts about the low tire pressure alarm, 30 seems to be the lowest you can run without tripping the low pressure alarm in cold weather.

I get 100 SPG (Smiles Per Gallon)! If I got anyhing less ... I'd walk.

I compiled a spreadsheet of my MPG's from basically January to April 2006. My average is 20.12 MPG, with a peak of around 21.6 MPG and a low of around 19. If interested I can pull the data to get actual numbers.

What's interesting is that while the price of gas has gone up since January, my MPG averages have gone down... So I'm increasingly paying more for fewer miles between refills.

I drive a 2005 6-speed M/T. I drive about 50/50 city / highway. Guessing that city driving averages around 40 MPH at 1500 RPM's flat. Highway is around 70 MPH at +/- 2000 RPM's flat. I use 87 regular (Texas) from Racetrac and QT gas stations.

Despite some folks not wanting to discuss the topic of MPG (with the price of gas going up as fast as it is and summer not yet really here) there seems to be quite a range in what people are seeing (12 to 20+ MPG). So, what the hell are folks doing that is getting them the 20+?

driving slow, i drive about 45miles a day, about 40 of it is highway, i dont usually go over 60 on the speedo (with the tires on there, its actually about 63-64mph) and don't accelerate hard

Bingo! Just found your problem.

There's no way around it. You can put railroad wheels on and still get 15 mpg if you drive 80 (if you're luck). I get 13 - 14 if I drive 80, but stay at 60 at watch your mpg go up to 22 or so.

When you ask about MPG, I think one should mention what year they have. I small underpowered truck running at 3000 RPMs will get less MPG than an engine that is bigger turning 1700 rpms. I have a 2006 for about a week and on the first couple tanks I have gotten around 20 mpgs.. I just read the article Xterra's DEATH VALLEY Initiation and he got 16 mpgs crawing around in 4 Hi and 4 LO all day.

Eric - Look to the left side of your screen, below a name you will find the info you're asking for.

Welcome from a fellow noob.

ok.. my bad.. I missed it that your X was listed under our name..

I've just finished tabulating my consumption for my 2000 Xterra from the past two years. I've got an excel sheet with all the data. I was interested in seeing if the 32" tires I got made much difference. Unfortunately, my two years of data didn't pan out to be enough since I was missing key months through the winter. This past winter was the only full winter of recording mileage in the two years.

As for the data, here are some figures:

Mar-04 - 14 mpg
Apr-04 - 16 mpg
May-04 - 16 mpg
Jun-04 - 19 mpg
Jul-04 - 18 mpg
Aug-04 - 19 mpg
Sep-04 - 19 mpg
Oct-04 - 19 mpg
Nov-04 - 17 mpg
Dec-04 - 18 mpg
Totals - 18 mpg (average for 2004)
Note: 2004 was all stock, stock tires.

May-05 - 17 mpg
Jun-05 - 18 mpg
Jul-05 - 20 mpg
Aug-05 - 20 mpg
Sep-05 - 19 mpg
Oct-05 - 17 mpg
Nov-05 - 18 mpg
Dec-05 - 15 mpg
Totals - 18 mpg (average for 2005)
Note: 2005 was stock up til November, Installed 32" (235/85R16) Tires (41lbs ea)

Jan-06 - 16 mpg
Feb-06 - 14 mpg
Mar-06 - 14 mpg
Apr-06 - 17 mpg
Note: All with 32" tires. This is the first winter recording milage. Once I rack up some summer driving, I will be able to tell how the tires compare.

All consumption listed in mpg.
Maximum seen so far = 21.9 mpg.

Distances adjusted for larger tire size using factor of 1.06, calculated according to rev/mile specs for tires.

I routinely get 19.5 mpg in a combination rural/freeway driving. I never exceed 65 mph and use cruise. When towing about a 1000 pounds it drops to 16-5-17.5 mpg. I now have 3000 miles on my machine.

I get 14-16mpg. Never anymore than 16 though. Selling the X, buying a Civic (I can't stomach it anymore). I drop $400 a month just on gas.

I haven't read this whole chain of posts. just putting in my 2 cents.

bought my '03 in dec. of this last year and made sure to run 92 octane as recommended. i got 13.5 mpg, needless to say, i was bummed. after some research, i discovered the different characteristics of octanes and engine timing. while on a trip in Iowa,(early april) i could only find 89 ethanol, so i ran it. the X jumped to 15.5, wow. so i started running 89. this last weekend, i thought i'd give 87 a shot, i was on a road trip, and could pay attention to the engine noises (listening for knock). so i check my mileage and wow! a sizeable gain. approx. 18 mpg (approx due to late reset of odometer missed miles were approximated fairly accurately) i'm on my second tank of 87 and i have already surpassed my average 260 miles on 17 gallons of gas.

happy days are here again.

also, i have been using acetone as a fuel additive for a couple months now and have notice gains in fuel economy. (do your own research if you want to try it, there are risks with these uncommmon practices and i don't want to be the guy that starts wild goose chases, i have accepted the risk) I'm not quite sure if it is totally paying off, cost of acetone for mileage gained, but, it makes the misses feel better and that is worth a couple bucks for sure.

Happy driving and on those bad gas days, just remember, 'damn, my X looks good'

Jeremy

Filling up with my first known ethanol blend fuel today spurred me to check out this thread. I thought I could post my 2005 gas log chart. I only convert from my truck notebook to a chart once a year, so no 2006 data yet.

This is for my 2002 XE 4x4 auto 3.3, stock 30" tires. Pretty stock truck, but I do carry alot of cargo around. Always use 87 octane.

MPG in red, gas prices in blue. The few longer gaps are where I was rotating out my home gas storage, so did not have a good reading.



Not sure what conclusions can be drawn, there's obviously alot of day-to-day variation with driving city vs highway. Reached a nice high in May, believe we had nice weather then so not using heater or A/C. But then dips as summer A/C and possibly summer blend gas. Doesn't go back up in the winter either. Some of this may be that I need a tune-up...

10

Holy mother of God! It's gas mileage, not your blood pressure!! Someone needs a hobby.

Hope you save the money from the cheaper gas by using 87 octane on your S/C X. You're going to need it when you have to repair the damage you're causing to your engine.

He has a S/C X?

That's what it says under his name...

In the same subject, just beware that you can't necessarily hear all knocking...

Up to 15.94 as of today.

Cool breakdown, SJ. Thanks for sharing the data.

41 mpg, highway, here. Oh, that's in our '06 Corolla!

15 city, fairly consistent... 17-19 highway

Took it for a trip, Up and down in elevation, speeds ranging from 30-85 for 260 miles and got 20.2MPG.

I get about 16-18mpg.

And to think, i sold a car that got 35mpg and could beat V8's; to buy this Xterra. <---demostrates my love for Nissan's!