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What mpg is everyone getting w/an auto xj?

My MPG calculations are in imperial units since I'm from Canada, but I've owned 3 XJ's and gotten great mileage out of all three. I only really keep track of highway mileage since city and off-road driving has alot of variables. I calculate my mpg on the same 400 mile highway trip which has 4 major mountain passes.

-1990 4.0/AW4 and 3.55's on LT235/75/15 tires and a 2.5" lift with the front bumper valence trimmed averaged 24-25mpg

-1998 4.0/AW4 bone stock and 3.55's on LT235/75/15 tires averaged 26mpg (driven like a sports car though)

-2000 4.0/5spd bone stock and 3.07's on P225/75/15 winter tires on heavy steel rims just averaged 29mpg in the winter with intermittent use of 4WD along the way! Needs a tune-up and curious to know if I can squeeze 30+mpg out of it after the tune-up and running the much lighter stock aluminum Ravine style rims in summer driving conditions.


Here's my observations:
-gas mileage decreased a bit on the 1990 after I removed the stock bumper valence. The 2.5" lift didn't seem to have much, if any impact on MPG though.
-I get my best MPG if I keep the RPM's under 2k, optimum from my findings seems to be around 1750rpm though.
-Cruise control seems to increase mpg by maybe 10%, but I can't use it much since the roads in my area are really curvy and there's alot of hills. I'm sure if I lived in a flat area and could use cruise alot I'd be able to add 3-4mpg to my numbers.

Overall, the XJ's I've owned have returned way better mileage than most other SUV's I've driven. When I was younger I always wanted to have a bigger lift and bigger tires, but now I'm pretty happy to run 235/75/15 all-terrains and a small budget boost which barely have any impact on my gas mileage.
 
20 mpg highway on 30'' street tires with 4.56 gears whining in the axles. Probably high teens in city

92 4.0/AW4
 
BotakBeng said:
For real?
I always have mine with Vons since is the nearest to my house.
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I see your location is Vegas, I've never been there. Do you have an oxygenated fuel program there? Can you have 50*, 35% humidity one day, and 10*, 75% humidity overnight? Some brands do better than others in our front range, Colorado climate.

djlarroc said:
isn't bradley and sinclair the same thing?
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I saw a tanker at my favorite Sinclair today. It said "Hill Petroleum" on the side. It also had a couple placards: One had the Sinclair logo, the other had the Sunoco logo.

Bradley does own a lot of old stations, but I think they all have the Bradley logo on the pump.
 
I usually use the local VONS gas, closest and cheapest. Mileage only differs with winter fuel.
 
94XJ currently: 16 hwy 14 city. 31" AT tires
I once got 21mpg hwy after a fuel filter and plug change, i was pulling a low utility trailer from Myrtle Beach to Moorehead City and got 21 mpg (ODD I KNOW). in fact currently when i pull my little trailer , my mpg stays the same or even goes up.:confused1

(just on a side note, i get better MPG with real Petroleum gasoline, and worse with Ethanol fuels. but it's impossible to find pure petroleum fuel in my area now)
 
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Our 89 got 24 mpg highway, before it burned out the head gasket. It was running too hot and lean.
 
A few years ago I took a trip from Denver (Golden) to Grand Junction. 1990, AW4, 3.55 gears, 235/75-15 tires.

Driving around town, we were averaging 16 or 17 MPG.

Driving West, like a bat out of hell, I stopped in Eagle to fuel: 13 MPG.

I don't remember fueling when I got to GJ.

After puttering around for a couple days, when I refuled for the return trip, I showed 23 MPG.

Drive like a bat out of hell back to Denver, refuel: 17 MPG.

Ethanol sucks...water, right out of the air. :mad:
 
Tbone289 said:
1 imperial gallon = 1.201 US gallons. But yeah, that still doesn't make up the difference. :rolleyes:
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maybe my math is wrong, but 25 mpg (imperial) over 400 miles is 16 Imperial gallons, times 1.2 is about 19 US gallons. that would make his mileage 21 mpg. seems possible :dunno:
 
blubullett said:
"Driven like a sports car averages 26mpg"

"29 mpg needs a tune up"

This thread isn't a competention. Please just tell the truth.
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Did you read the part about Imperial units since I'm in Canada? So 26mpg Imperial becomes around 21 US mpg, and 29mpg Imperial becomes around 24 US mpg figures. Maybe our definition of driving like a sports car is different, but averaging 70mph through the mountains is fast enough for me!


I don't really see what's so outrageous about that; alot of people on NAXJA with stock or near-stock XJ's are getting the same mileage as me.

I think there's alot of lower MPG numbers flying around because the majority of people on a site like NAXJA have modified their trucks with bigger tires, lift kits, roof racks and winch bumpers which all hurt mileage to a degree. You'd be really surprised how fuel efficient a stock XJ is without all the add-ons.

BTW, here's a really easy MPG calculator to go from US to Imperial MPG if you'd like to check my numbers:
http://tdiclub.com/misc/conversions.html
 
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Okay, I give. I'll admit I've never particularly cared about Imperial gallons, but how do you come up with miles per gallon metric?
 
hubs97xj said:
Okay, I give. I'll admit I've never particularly cared about Imperial gallons, but how do you come up with miles per gallon metric?
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It is not metric, it is US gallons versus Imperial (UK-Canadian IIRC).

Gallons are not metric, liters are metric. KMs are metric, not miles.

Km/litter is metric.
 
And hence the confusion.

Thanks Mike, I'm well aware that gallons aren't a metric unit, nor are miles, which is why I asked how he was claiming metric mpgs...
 
hubs97xj said:
And hence the confusion.

Thanks Mike, I'm well aware that gallons aren't a metric unit, nor are miles, which is why I asked how he was claiming metric mpgs...
Click to expand...

I kinda figured you did. I just decided to clear the air with some facts, LOL, instead of bait, LOL!!!

But I am sure there are bunch of silent readers who don't know the differences. Sad to say. I never really had a sound grasp on the metric units, or even some US units, until I was forced to live them day, night, sleep, dreaming, in my first Chemical engineering class.
 
stroked88 said:
maybe my math is wrong, but 25 mpg (imperial) over 400 miles is 16 Imperial gallons, times 1.2 is about 19 US gallons. that would make his mileage 21 mpg. seems possible :dunno:
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Your math is correct. When was the last time you got 21mpg in your XJ driving like "a sports car?" ...and 24mpg when you need a tune-up?

Possible--yes, I suppose-- but those numbers are really good when you consider the other averages in this thread.
 
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Tbone289 said:
Your math is correct. When was the last time you got 21mpg in your XJ driving like "a sports car?" ...and 24mpg when you need a tune-up?

Possible--yes, I suppose-- but those numbers are really good when you consider the other averages in this thread.
Click to expand...

I wonder if high density cold air makes a difference. He was in Canada I think? Or could the computers for Canadian jeeps run the engine leaner than Californika-EPA programs here?
 
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