i got a 1998 4 cylinder with 31's and ive been clockin my mileage with a full tank and have been gettin roughly 200-220 miles from the 19 gallon tank. i figure it out to be around 11-12 mpg...is this normal and if not any suggestions of what i could do?
yea ive heared that u can get close to 50-60 after the light but what was weird is before i shut it off i was right above the red section with no light on and then i started it up and then i was clearly below the red line with the light on
Don't go by the gas gauge or low fuel light at all, both are notoriously inaccurate. Most say they are empty when there is still 3-5 gallons left. Heck, mine shows it is half-full within 50 miles after I fill the tank, and it shows nearly empty when the tank still has ten gallons in it. Go by your odometer instead and note the number of gallons your Jeep takes after a fill-up. That way you'll know your true range and mpg.
Don't go by the gauge or low fuel light at all, both notoriously inaccurate. Most say they are empty when there is still 3-5 gallons left. Heck, mine shows it is half-full within 50 miles after I fill the tank, and it shows nearly empty when the tank still has ten gallons in it. Go by your odometer instead and note the number of gallons your Jeep takes after a fill-up. That way you'll know your true range and mpg.
yea thats a good point i completly forgot the gauge is really inacurate...because after all this i went and filled up and got roughly 14-15 gallons when it was displaying i was below red...thank you for your input
I have a 98 and it's in need of a fuel pump/sending unit. No owner's manual, can someone tell me what size tank is stock on the 98's? 4 cyl, 5 sp. Thanks for your help!
I've read this before but I have the factory build sheet (window sticker) for my '99 sport and it says I have a 15 gallon tank, which the pump seems to confirm. So the TJ gas tank puzzle continues...
Boy and I felt bad I'm getting about 12 MPG with my 6cyl have 31X10.5X15 tires.Does anyone think the California emissions make MPG or horsepower less?
Have a manual trans
Do not forget the odometer may be off a bit also with larger tires. No way of really accurate mileage checking in my book unless all has been recalibrated. Who cares, it is a Jeep.
About 13 MPG, 2000 TJ with autotrans, stock suspension, 30" tires. When I check mileage, I usually drive 600-800 miles and record total miles driven and total gas put in the tank for 3-4 fills. I get slightly better MPG with 92-93 octane than with 87, but probably not worth the added cost of premium vs. regular. Usually get about 240 miles on 19 gallon tank. I think when it was new I got about 280 miles on a tank.
i have an 06 4cyl 6 speed, if i keep my foot out of it and actually get to 6th gear i get about 21mpg, i have 235/75-15s which i think are a tad smaller than 30's? so their not aweful big tires but bigger than stock, i always fill up when i touch the red line and that is normallly about 15 gallons and on those 15 gallons i can get anywhere from 260-300 miles, never ran it to the gas light so im not sure if it is really a 19 gallon tank or not?
Have you calibrated your speedometer? If not...I think the stock tire size would be roughly 27.5 inches in diameter. If you are running 31s without calibrating you are going about 55 mph when your odometer reads 50. If so you are going 110 miles for every 100 your odometer reads.
With my 30" tires, my speedometer runs higher than actual speed. Checked against my Tomtom GPS, and also when I see one of those roadside portable radar speed displays the LEOs put out. So when my speedometer reads 25, I'm actually going 23. I think the difference scales with speed, so when my speedometer reads 50, my actual speed is about 46.
I've been tracking my mileage for about a month. Religiously, every fill-up gets recorded in my excel sheet. I changed my plugs & wires a month ago, that's why I don't compare anything prior. I always run premium (personal preference), and I stay away from the low-budget gas stations.
Over the past month, my MPG ranges from 14.62 MPG to 17.83. The way I drive doesn't seem to impact my mileage. When I drive carefully and use the skinny pedal sparingly, I sometimes get better, sometimes worse mileage.
One of my better MPG's was on a 4wheeling trip. That confused the heck out of me.
My Tacoma would fluctuate, but it was directly related to how hard I pushed it. It would also fluctuate much more than 3MPG.
Is anyone else experiencing this same kind of pattern? (99 Sport, 4.0, 4spd auto, unknown -believe stock- gearing, 31x10.50)
I'm still learning what I have. The more I read (and drive) the more I believe it does have some mods done. I have a 4spd auto, which was supposedly not available in 99, and I believe I have some budget lockers both front & rear - last camping trip I dug 4 holes, straight down.
If you understood what "premium" really meant, you would no longer run it. Premium is just a term gasoline manufacturers use to entice people to think it is somehow better, has more power, more cleaning additives, helps the engine run better, etc. but none of those could be further from the reality of what it really is.
The only difference between 87, 89, and 91 octane fuels is that 87 is the easiest/fastest to ignite. 89 burns a little slower and is more resistant to higher compression before it self-detonates, and 91 burns a little slower and is a bit more resistant to higher engine compressions yet. That is it. All three have the same amount of additives, fuel injector cleaners, etc. The gasoline manufacturers describe their "premium" fuels in such a way as to make some think they include more/better additives but they don't in reality.
Octane is simply an additive that is added to slow the gasoline's burn rate down and to allow it to withstand greater compression levels without premature ignition from excessive compression.
Why do different octanes even exist? Because some engines have higher levels of compression to produce more power. Corvette, Lexus, Mercedes, Mustang 5.0L, etc. are high compression engines so they need fuels that can resist the higher compression levels without premature detonation.
But if your engine was not designed to produce such higher levels of compression, then there is absolutely zero benefit to using a higher octane fuel. Zero, nada, none. If your engine does not ping with 87 octane, then there is zero benefit to running 89 or 91 octane. None. All doing so helps with is by contributing to the profit margin of the gasoline manufacturers. It costs them about a penny per gallon to turn 87 into 89 and a penny more to turn it into 91. But they charge 10-30 cents more so it is far more profitable for them.
Energy-wise, a gallon of 87 octane has precisely the same energy content a gallon of 89 or 91 does. Running 89 or 91 or 104 octane fuel in an engine that was designed for 87 is a 100% waste of the extra money it costs. And no, the engine won't run any cleaner either. There are ZERO benefits for any of our Wrangler engines by running anything with more octane than 87.
:wavey:
If it is pinging all the time, then yes but that also indicates an engine problem like a carbon buildup. It should not ping all the time so if it does, your engine needs work... like having it de-carbonized.
Occasional pinging like just before you downshift to go up a steep hill is normal.
Today's Mechanic Tip - Unless you are on a road trip (READ - grocery getter or work commute) Keep your fuel tank above the 1/2 full mark or what would equate to half a tank. The fuel pump being mounted in the fuel sending unit relies being submerged in the fuel to keep it cool. #1 cause of fuel pump failures is getting over heated.
Mileage is all in the right foot...baring modifications that add weight and aggressive tires giving more rolling resistance. Learn what type of driving get's you the best mileage (RPMs, shift points, accel rate...). Even a bad alignment will rob you of 2-3 mpg.
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