Bugleboy

Yahoo! My new vented tailgate got here last night and put it on this morning. Looks really sharp! This is, as you may remember my post from last week, to replace my factory gate that was stolen off my truck. Yes, I already know about possible fuel mileage decreases, but am hoping the vented style will help with that. Altho, fuel mileage decrease can't really hurt me that much as I am only getting about 12mpg in town and then 11mpg/hwy when I pull my trailer (7500#).

Got pics posted in my gallery awaiting approval.

TRCM

WOW !!!

do you drive like you're at the dragstrip ??

I don't even get that bad towing 10k @ 65 mph (I get 13.5 - 14 mpg).

if yer seriously getting that bad for mpg, you have some issues with the truck that need to be fixed.

Bugleboy

HA HA...no, I don't drive like that (at least it doesn't seem that way). My speedo is off due to my tires (235/85/17's) by 5mph, and don't really know how to calc the offset to get true mileage. I have had the truck in for many a service call and have asked about the mileage, but get the same ol' "it passes our diagnostics." One of these days I will bomb it with an Edge and a FASS system, which I hope will help with the mileage issue. This is my daily driver as I am a Computer Tech and put about 30-60 miles a day on it stop and go. When I first got the truck, I conciously kept it under 2K rpm to keep the turbo out of the picture, but that only gained me an extra 1/2 mile to the gallon.

I don't even know where to start looking if there are other issues involved.

Thanks for you input

crobtex

You might want to check your LP ad IP. I have heard some say that bad milage is sometimes caused by the VP44 going bad. I hope that's not true in your case.

Bugleboy

Both of those were replaced November 2004, as was my tranny in April of 2005, and my starter and my brake booster pump (I know the last three have nothing to do with mileage but went thru a really BAD first year of ownership of this truck.) I thot the IP and LP would make the difference but no dice.

Thanks!

TRCM

off by 5 mph at what speed ?? what were your stock tire sizes ??

you can do a ratio of (235/stock)*speedo reading and that will be your true mph.

If your stock tires were 215's, the speedo is off by about 5-6 %. If you changed rim sizes, it can make a difference also.

Even with this, you're only getting 13 mpg. To get that unloaded, I'd have to be dumping smoke 75% of the time in mine.

Bugleboy

Off 5mph at 45mph and above. Used my GPS to gauge my speed on my last couple of hunts on the interstate.

Stock tires were the 215/70/16's (am recalling that from memory, does that sound right?)

How can I factor in your formula to properly figure my true mpg? Or is it possible?

Bugleboy

oh yea, and no smoke... altho I have tried....

TRCM

if you do (235/215) * speedo reading, it will get you very close to true speed. I don't think the sidewall height will make that much of a diff. My stock tires were 215/85 x 16. I now run 235/85 x 16, and my speedo is off by about 6%.


What I have alway done, is figure it out for speedo readings of 25, 35, 45, 55, 65 and 75 mph. then you know what you are really doing, and can guess in between.

or you can just figure the speedo reads 10% low.

for mpg, just take and substitute the odometer reading for the speedo reading in the above formula.

IE (235/215)*450 mile = 491 miles traveled

or 450 miles + 45 miles = 495 miles traveled


somethign else you need to consider, gps doesn't show road miles, it shows straight line from point a to point b. by that, I mean you drive on the surface of the ground, but the gps calculates it straight thru the ground.

I took a trip to fl once, and the gps said it was 700 some miles, but it was actually closer to 800. gps doesn't follow the earth's surface when it calculates distance (at least my old unit didn't).

Bugleboy

good point on the gps readings, I had noticed that also, but it seemed to give me a good mph reading.

I will try your formula with my next tank (prolly filling up tomorrow).

Thank you very much!

govspringbounce

If someone hasn't already suggested, put a hose clamp around where the tailgate attaches to the truck, lower point, the side of the tailgate that has the slot in it. That way, they can't simply lift it off.

Bugleboy

govspringbounce - yes, that was suggested as was drilling a hole where the cables go and adding a large washer/lock washer and screw. I will be doing both.

This new gate does have a lock on it, but every added level of deterance helps!

Thanks!