I was told that if you have a leaky injector, your oil will be thin and you should be able to tell just by looking at the condition of the oil. I don't know if this is true, but I imagine it is if you have a really bad leak.

 

I had my oil analyzed last change @ 69K miles and had <0.5% (std is <2.0%). I was still getting the 12 mpg ave so I am pretty sure it's not an injector.

So if I have the higher flow airbox with the stock cat and muffler I shouldn't see any real change in mpg?

 

I wouldn't think it should be that bad.

 

might go down slightly but not down to 12's. is your mileage all city?

 

Unfortunetaly, I'm in Southeast L.A. That's Lower Alabama.

 

yeah that is kinda far for a gear swap.

 

Maybe 75% city. But I can only get around 15 mpg on highway driving.

I could accept the 12'sfor city driving IF I was getting 18's on the highway

 

When I was driving from New Orleans to about 100 miles north of Houston to trade in my Black '064x2 on my inferno red '06 4x4 I got hand calculated 22-23 mpg holding around 70 with 18k miles on the odometer. With my new truck I get maybe around 17-18 straight highway, 14-15 city and around 12-12.5 pulling my 5x10 cargo trailer (just about everyday) that cant weight more than 2500lbs. Old truck would get 15-16 pulling the trailer around the city, straight city with the new truck gets me around 11mpg. The first truck I bought new and the first few thousand miles were depressing because I was gettin garound 10mpg, first tank was 9mpg but it got better very quickly. I got the new truck with 5k miles on the odometer and now have 17,500, maybe this truck is taking longer to break in? I know 4x4 doesnt help but damn, I never thought it would suck 4-5 mpg from my economy. The truck did have just an aftermarket muffler when I bought it but I put an aero4040 where the cat should have been but really didnt notice a significant change in mpg. I am at about 6000 miles since my last oil change (I usually change every 5k) and am going to get a sample to send in for testing. I dont think anything is wrong but I want to check anyway.

 

'05 here... stock except for a KN filter in the stock box... hand calc'd in the city is 17-18.... best I have done on the highway was 21.5 traveling from NC to NH. coming home was worse but didn't care for mileage...just wanted to get home.