Another Gas Mileage Thread

*joekrz* · 01-24-2005, 08:20 AM

I filled my tank on Thursday last week and put on 40 miles running around town and to work on Thursday and Friday. Saturday I went on a trip. My destination was 160 miles away. There was a snowstorm here on Friday and into early Saturday afternoon that dumped 8 inches of snow. Because of the bad road conditions, I had it in 4wd the whole time on the way there. My average speed was between 65 and 70 mph. When I left to return home later in the day, the roads were plowed and cleared real well, so I didn’t have to use 4wd for the return trip and I had the cruise set at 70mph for the duration. By the time I got home I had 360 miles on the odometer and the gas gauge was below E (light was on of course). I stopped at the gas station and it took 24 gallons to fill it back up. So 360/24 = 15 mpg. Considering 160 miles of that was in 4wd the whole time I think 15mpg is pretty good. I would have to believe that I could have got 17+ mpg if I hadn’t been running around town and using 4wd for 160 miles of that trip.

I have a Crew Cab, 4x4 with off-road and big tow.

**HudsonValleyTitan** · 01-24-2005, 08:32 AM

I'd love to see a real study comparing mileage differences between 2WD and 4WD. Not a 4X4 vs a 2WD Titan but a 4X4 using 4WD and one not using it. I'd bet there's little to no difference because in our trucks, (from what I'm told) the front end is always turning, just not powered until 4WD is engaged. That would tell me that highway mileage shouldn't really change because all that mass is turning anyhow. Anyone else agree?

vindication · 01-24-2005, 08:54 AM

wait I thought the Titans held 28 gallons? how the hell did you get to only put 24 if it was bellow E?

*joekrz* · 01-24-2005, 08:58 AM

Quote:

Originally Posted by vindication

wait I thought the Titans held 28 gallons? how the hell did you get to only put 24 if it was bellow E?

Because there was still 4 gallons in the tank even though the gas gauge was below E.

On every vehicle I have owned, I have been able to run the gauge below E and still have gas. I can do the same thing on my current '01 Isuzu Rodeo. Just thought it was normal that gas guages worked that way.

logicjunky · 01-24-2005, 09:02 AM

Quote:

Originally Posted by vindication

wait I thought the Titans held 28 gallons? how the hell did you get to only put 24 if it was bellow E?

His sending unit is off. Mine kicks on the E light with at least 6 gallons of gas left everytime, typically 7-8 gallons left. I need to replace it but I am in no hurry. Common issue, do a search on other gas mileage threads you'll find it.

*joekrz* · 01-24-2005, 09:03 AM

Quote:

Originally Posted by HudsonValleyTitan

I'd love to see a real study comparing mileage differences between 2WD and 4WD. Not a 4X4 vs a 2WD Titan but a 4X4 using 4WD and one not using it. I'd bet there's little to no difference because in our trucks, (from what I'm told) the front end is always turning, just not powered until 4WD is engaged. That would tell me that highway mileage shouldn't really change because all that mass is turning anyhow. Anyone else agree?

Nope, don't agree.

While some of the front end components may be turning, it still takes more power to turn the front wheels when the 4wd is engaged because of the resistance of the drive train components and thus your gas mileage goes down.

Edit: Page 5-19 of the owners manual specifically states - Four-wheel drive operation lowers fuel economy.

vindication · 01-24-2005, 09:04 AM

hmm interesting on the sending unit. is there a set amount by nissan when the light is "supposed" to go on?

*joekrz* · 01-24-2005, 09:26 AM

I don't think my sending unit is bad, because my gas gauge works fine. However I have noted, like logicjunky, that my light does come on when there is 6 gallons left. I would rather have it that way, rather than come on when there is only 2-3 gallons left.

rarjar · 01-24-2005, 09:30 AM

Quote:

Originally Posted by joekrz

I don't think my sending unit is bad, because my gas gauge works fine. However I have noted, like logicjunky, that my light does come on when there is 6 gallons left. I would rather have it that way, rather than come on when there is only 2-3 gallons left.

Same with mine, although I have noticed over time that where my gauge used to show above the "full" mark when I filled the tank, it now registers slightly below full, even when I top it off. I guess if it keeps getting worse, I'll eventually have them replace the sending unit.

SHIPREC13 · 01-24-2005, 09:31 AM

Did I read correctly you were in 4 wheel drive going 65-70?? I thought you weren't supposed to drive above 45 in 4 wheel drive.

logicjunky · 01-24-2005, 09:59 AM

Quote:

Originally Posted by joekrz

I don't think my sending unit is bad, because my gas gauge works fine. However I have noted, like logicjunky, that my light does come on when there is 6 gallons left. I would rather have it that way, rather than come on when there is only 2-3 gallons left.

Those who posted in other threads with our same issue had their sending units replaced and now their E light comes on with like 3 gallons left. Also, you'll notice that after approximately 30 miles of driving right after you fill up, your gauge will read that you have used 1/4 of a tank. When if fact you have used about 2 gallons. That's why I think the unit is bad, that, and the E light kicking on so soon.

logicjunky · 01-24-2005, 10:01 AM

Quote:

Originally Posted by SHIPREC13

Did I read correctly you were in 4 wheel drive going 65-70?? I thought you weren't supposed to drive above 45 in 4 wheel drive.

Yeah, that's a little fast for 4WD, huh?

I believe no faster than 45mph is the recommended speed.

*joekrz* · 01-24-2005, 10:28 AM

Quote:

Originally Posted by logicjunky

Those who posted in other threads with our same issue had their sending units replaced and now their E light comes on with like 3 gallons left. Also, you'll notice that after approximately 30 miles of driving right after you fill up, your gauge will read that you have used 1/4 of a tank. When if fact you have used about 2 gallons. That's why I think the unit is bad, that, and the E light kicking on so soon.

Actually I have 36 miles on right now after filling up on Saturday night and it is slight below the full mark. Nowhere near the 3/4 mark as you suggest.

*joekrz* · 01-24-2005, 10:41 AM

Quote:

Originally Posted by SHIPREC13

Did I read correctly you were in 4 wheel drive going 65-70?? I thought you weren't supposed to drive above 45 in 4 wheel drive.

Page 5-22 of the manual (Starting and Driving Section) states - The 4H position provides greater traction. Avoid excessive speed, as it will cause increased fuel consumption and higher oil temperatures, and could damage drive train components. Speeds over 62.5 MPH in 4H is not recommended.

I don't think 3-8 mph over the recommendation is going to hurt anything. It's just a recommendation only, not something that has to be adhered to for fear of something going wrong.

I have driven in 4WD at those speeds on my past vehicles (and even my current '01 Rodeo) and never experienced any problems, so I am not too concerned.

Some of you should read the manual sometime. There is a lot to be learned instead of pulling a number of 45mph out of a hat.

tnbowhunter · 01-24-2005, 10:48 AM

Quote:

Originally Posted by joekrz

Page 5-22 of the manual (Starting and Driving Section)

Some of you should read the manual sometime. There is a lot to be learned instead of pulling a number of 45mph out of a hat.