Something's Gotta Be Wrong

DownhomeVA · October 8, 2007

I'm seriously worried about this...

I bought this truck used a few months ago. I was (and still am) totally prepared to suffer the poor gas mileage in the name of owning a B-F-T.

Be that as it may; it seems my gas mileage is considerably lower than everyone else's on this forum, and it has me concerned I got a lemon.

Last time I checked, I was getting 9.3 mpg in the city.

Should it REALLY be that bad?

Not towing anything, nothing in the bed - just driving to and from work through the suburbs.

What gives?

Draenor · October 8, 2007

I average 12 hwy/city. I think 9mpg is a hair low but I would consider normal(someone with a heavier than normal foot.) How many miles, and have you done any maintenance?Any modifications? I see in your sig you have larger tires, has the speedo been re-calibrated?

DownhomeVA · October 8, 2007

I have a fairly heavy foot. It's got 43K on it. No, I haven't done any real maintenance other than an oil change. I've only had it since June. The tires are 265/75/16. I have some aftermarket exhaust, "Turbos" I was told by a local grease monkey. I don't know what else... also have no idea if the speedo has been re-calibrated either.

9.3 mpg freakin SUCKS...

Draenor · October 8, 2007

I have a fairly heavy foot. The tires are 265/75/16. I have some aftermarket exhaust, "Turbos" I was told by a local grease monkey. I don't know what else... also have no idea if the speedo has been re-calibrated either.

1.The heavy foot dont help.

2.It the speedo wasnt recalibrated, you DIC is not getting accurate info on calculating the mpg's. Try doing a manual recording next time you get gas.

3.Im sure whatever the exhaust you have probably doesnt help too much either.

Ranger · October 8, 2007

Yeah that's about what I'm getting, so I'm trading it for a 1500 5.3. It's a good truck but just economically unfeasible at this point.

asilverblazer · October 9, 2007

I have a fairly heavy foot. It's got 43K on it. No, I haven't done any real maintenance other than an oil change. I've only had it since June. The tires are 265/75/16. I have some aftermarket exhaust, "Turbos" I was told by a local grease monkey. I don't know what else... also have no idea if the speedo has been re-calibrated either.

9.3 mpg freakin SUCKS...

DIC or not your odometer is off which I'll bet you are using for your calculations, menaing you are traveling farther on a tank of gas than you are being told by the odometer. Also the larger tires are raising your final drive ratio. Bad for city MPG good for highway MPG. Exhaust is probably lowering your bottom end torque, you need this to get the truck moving, happens a lot in the city, so you compensate by giving it more gas. Heavy foot, well thats not gonna help your MPG. A mild tune up won't hurt. (Air filter, etc...)

DownhomeVA · October 9, 2007

what's DIC?

while we're at it...

what's NBS?

what's OBS?

and does my exhaust suck or something?

Draenor · October 9, 2007

what's DIC?

while we're at it...

what's NBS?

what's OBS?

and does my exhaust suck or something?

Drive Info Center....the instrument cluster.

New Body style

Old Body Style

As for the exhaust, the Vortec likes a bit of back pressure to get a decent torque curve. Flowmasters ,cherry bombs, and straight pipes are meant to give straight HP or figures in the upper RPM range.

DownhomeVA · October 10, 2007

can i get that in dumb guy English?????????

So...... i need to drop the "turbos" and go with flowmasters?

by the way your sig is friggin hilarious

CHevyHD4x4 · October 10, 2007

In my HD (11,500 miles) on the clock in town I'm getting 9.9 ! And going up slowly but I have a tune exhaust and bigger tires and a heavy foot.

asilverblazer · October 10, 2007

can i get that in dumb guy English?????????

So...... i need to drop the "turbos" and go with flowmasters?

by the way your sig is friggin hilarious

The best is to go back to factory for low end torque, if you plan on building the motor to run high rpm's (like a race engine) then the mufflers on it will be better.

Nytemare · October 11, 2007

I got my 03 with 75k KM on it, whats that about 45K miles or so. I had to replace the plugs and wires in it, even though they say they're good for 100 K miles, I don't trust that. I had one wire that had infinite resistance, meaning it was broken, and my plugs were at about .080 gap and white in color.

NGK TR-55 copper plugs are good and I bought some MSD wires, they were only 15 bucks more than a stock set and have a Life time warranty so I thought it was a good investment, but any performance or premium wire set is good.

I find I get about 30-40 km more per tank since I switched my oil to royal purple too (not much, but a buck is a buck). I also have a bit of a heavy foot, and I still noticed a gain. I am switching the whole drive train to RP as soon as the maintenance schedule is up.

Also look into getting a mail order tune, westers, wait4me, etc tunned for fuel economy, you should get about 1-2 mpg more.

Also, do what asilverblazer said too, and the speedo re-cal is also a good idea. You should be up around the 12mpg region than, not bad for a big truck with a big engine and a driver with leaded shoes.

Schmids5.3l · October 11, 2007

Nice truck!! looks sweet. I'd get a tuned PCM for economy. I don't think different exhaust will make that much of a difference.

Don't worry, you don't have a lemon. Many people on here have the 5.3, that's a good difference in gas consumption, not to mention you have the heavier 3/4 ton HD. I probobly only average 14 in the city, I know I get 17 mixed, and my commute is mostly highway.

DownhomeVA · October 11, 2007

thanks for all the input fellas - i'm not so worried about my purchase now.

BigJayDogg3 · October 12, 2007

If I remember correctly, if you get a mail order tune, you can have them tune the truck for economy when you are driving regularly, but when you hit the tow haul button, it shifts back into a more peppy mood. And if you want, you can have the tow haul button be a hot rod button.