Tires and MPG

**lowufo** · 02-16-2009, 08:46 PM

Can anyone explain why you can run CTD's with 33"-35" tires and still get 18mpg, yet see a significant drop in mileage with the DMax with anything bigger than stock??? I'm running a PPE, 4" turbo back and intake mods and barely get 16 mpg running 305's (same height as 285's) doing 65mph. Love the truck but the mileage is frustrating!!

**delong_1** · 02-16-2009, 08:48 PM

have you changed the tire size with your ppe, if not your mileage is a lot better than you think

**lowufo** · 02-16-2009, 08:50 PM

I did, everything double checked with GPS and hand calculated. Was getting a solid 19+ mpg with 265's.

**delong_1** · 02-16-2009, 08:53 PM

they are heavier and cause more drag. have you done anything different besides the heavy wheels and bigger tires. could the winter blend fuel have caused the mpg drop?

**lowufo** · 02-16-2009, 09:00 PM

Nothing different, don't know about the winter blend issue. Is it common for mileage to drop during winter? New to diesels. Anyway, 3 friends with CTD's all getting a pretty consistent 18mpg with smallest tires being 285's and pretty much stock rigs.

**delong_1** · 02-16-2009, 09:05 PM

usually during the winter mileage will go down a bit. dodges are well know for getting pretty decent mileage.

**HumboldtDmax** · 02-16-2009, 10:01 PM

even with that small amount of lift it can create a lot more drag
I'm getting about 15 MPG at 65 in a straight line with no hills and all the goodies
maybe Cali diesel sucks

subparwelder · 02-16-2009, 10:43 PM

Mine sucks as well. Only have about 9k on it and praying that it gets better with time. Getting 14-15

**ob_1jr** · 02-17-2009, 12:48 AM

Hahahaha dodges are known for getting good mileage??.....maybe empty, but you tow anything with them and it drops...of course I haven't driven a cummins, but I know their gas engines suck. I think the whole mileage thing is inflated anyway. Unless you ride with someone or follow them and see how they drive and how much they fill up with i would say the information is bad. Most people go by what their computers say.....at times I could be getting 30 mpg if i did that. it all needs to be hand calculated.

BUGGYS DMAX · 02-17-2009, 03:15 AM

You Lose All Ur Mileage Down Low, Thats Where Cummins Makes All Their Power, Thus Improving The Mileage Compared To The Dmax Or Any V-8 Making Power A Little Higher In The Powerband. Hope This Helps