Some questions about the 'ol girl

[Eastcoastrunner]

Ok. First off, i have an 03 v8 limited runner
Some questions/concerns....they aren't major but I figured there are many knowledgeable people on this board, so here goes:

(1) Fuel economy. I find it seems worse then other people with the same make get...i do 100% highway driving, don't use cruise, don't go above 110km/h or 70mph, tach rarely breaks 2k ( i don't stomp it, it's a smooth transition).
Best i can get is 16.5 miles/gallon. Often times it's between 15-16.
I have a cracked exhaust manifold, and the odd time i get a CEL but it goes away....i figured it was related and was told it was an o2 sensor, rear right (which i replaced new from toyota 3 mths ago, still happening).

(2) rattle sounds/creek sounds. Seems it comes from back, but anyone else deal with this a lot?

(3) buzzing sound...when going down hills. Brake control?

 

[Sants]

The worst my 04 v8 has gotten was 15 mpg and that is city. Is't usually 15.5 - 16 mpg.

On a trip that was about 50% highway it was a solid 17mpg. That was cruising between 65-75. Still as good and even better than my old 01 pathfinder!

I would suspect I could get 19 all highway but wouldn't expect any more than that.

My truck only has 35,000 miles on it so it's still young.

As far as the creek in the back, does it come from the rear drivers side? Mine does it when I go over bumps. Annoying! It is more of chirp though and if I hit the jack panel it does it. I am waiting until the spring to pull it off and fix it with stripping or tape.

My dome light has a very quiet but annoying rattle.

 

[Eastcoastrunner]

ya i would expect 18-19 mpg all hwy when not hammering it, actually babying it.
I've got about 120k miles on the clock. Recent oil change/air filter/plugs/seafoam done. I maintain it very well.

 

[Sungod]

I get about 15 in the city with my average speed being around 22-25 mph. On the highway I get about 17. Slightly more in the summer.

 

[ARK_SWAMP_RIDER]

I'm in the same boat, I'm getting 15-16 and use to get 16.5-17.5. That's 60% highway. If I touch the interstate, even driving 65mph instead of 70mph, you can count on about 15.

 

[JB.]

(2) creek sounds. Seems it comes from back, but anyone else deal with this a lot?

The two that come to mind are the hatch latch and rear seat upright latches. For the hatch, I haven't found anything that works better than WD40. I have to re-apply every couple of months.

 

[ryangab]

As far as mileage goes - about 18mpg on highway going about 70...

A recent road trip I was flirting with 20 the whole way. going about 70. It seems like the truck gets settled in on long trip and it runs smoother.

I had a couple creaks with the seat latches(next the button to fold them down) I just folded the seats down and wrapped electrical tape around the latches. No more noises!

 

[rockwall]

I'm getting a solid 20mpg on the highway and about 16 in suburban driving. That's not bad for a full time 4WD V8 that has a small lift.

I have had several rattles that all drive me crazy. Specifically my sunroof, the hatch and second row seats. Thanks for the idea of the electrical tape. I find that white lithium grease works better than WD40 or any other "oily" type lubricant. It goes on thicker and lasts much longer.