MPG question... is this normal?

I have a 2008 Automatic V6 Access cab w/ 25k for about 1 month. I put an afe dry flow filter on and added new tires. The tire size changed from the factory 245 dunlops to 265 75 16 goodyear tires.

My mpg's are averaging 16-17 at this point. I had it on the highway this weekend and got about 17.5mpg. Just doesn't seem right for a 4x2...

Does anyone think I am having issues or is it just the slightly bigger tires?

I put my fuelly sig on if you want to check it...

Thanks,


PS. don't get me wrong, I'm not dissapointed or bitchin or anything, just concerned if there might be something wrong with the pickup I just bought.

 

Do you know the mileage from before the tires??
And have you used the tire calculator on the site to figure out the mileage correction??

 

I only had the stock tires for one or two fuel ups, I didn't have my fuelly account then, but I'm pretty sure I calculated getting 21 on a road trip to corpus.

 

Yea, no way did those tires drop your MPG that much... something has got to be off.

 

Specially if you went 245 to 265- that's like a .4% adjustment- which is nothing. I'm kind of interested to see what the result is.

 

Thanks guys, but what would be the plan of attack? Dealership? It is under warrenty another 10k or so

 

How exactly are you calculating your MPG?

What tire pressure are you running?

What type of driving are you doing?

 

Tire pressure is at 35psi

When I fill up I stop on the first click of the gas pump. I drive in heavy traffic most of the time. On a full tank of Austin traffic on highway 35, I got 14mpg!?! The thing with that is I did some highway driving this weekend and I still only got 17.5. running 70-85mph

I just made a fuelly account and that is how I have been tracking it. Before that I would divide the miles drivin by the number of gallons it takes to fill up.

 

Are you taking into consideration the difference of distance with the larger tires? When you put larger tires on, the actual distance you travel DOES NOT match the distance your speedometer is showing you.

With larger tires, your TRIP distance information is going to be LESS than the actual mileage you are traveling.

Do you have a GPS?? You can compare actual trip information (on your truck) with the GPS.

 

well there you go. for maximum MPG the ideal speed is 55mph. take it down a notch and dont go over 70...ever. try your best to keep your RPM's under or at 2k, drive like you have an egg under your foot. Im running 33" tires and my last tank averaged 18.2 mpg and I did account for my bigger tires, I think its like a 5% increase. so instead of what my ODO showed, 308 miles, I actually got 323 miles.

 

You may be right, I will check my tire % increase, thx bud

don't you have a 4x4? I can't believe I'm getting worse mpg than a 4x4s

 

from the online tire size calculator


Here is the tire size calculator, can someone tell me what the true miles traveled if I did 300miles on the trip?

 

You take the % difference in the Circumference add 1 and then multiply your odo distance. Soo...300*1.039=311.7 iirc.

 

Brunes, thanks for the help.

went into my fuelly account and updated the miles drivin.... raised the mpg's on my profile almost 1 pt.

 

Im running goodyear 285/75/16 and average about 19 mpg. It's all in you driving dude.

 

I have a stock dc trd 4x4 with the 6 cylinder and just got back from a road trip to Texas. I used cruise control 90% of the time and after 2600 miles I got 23.4 mpg. I am very pleased, around town here in NC I was only getting 19.2 -19.4 but around town for me doesn't mean much traffic. Five o-clock traffic in Boger City is 3 cars in line at one of the 4 or 5 stoplights in town.

 

thx all, i'll back off the gas

 

Also what gas are you using? Use quality fuel like cheveron/quik trip/shell/ect

Cheap costco type gas can kill your millage a few points too. I did the math once, I saved more running chevron 91 than I did costco 87 on millage bonus (let alone the car ran like ass).

Also as a side note, my prerunner was pretty consistent with 18.7 no matter what I did (excluding towing).

 

18.7 is more like it. I'll try a better brand and see if that helps also.

 

I don't know how you guys do it, I drive slower than a grandma and hardly touch the gas and get 14 mpg in the city and if I'm really good on the highway then ill get a little over 16. I have a 3 inch lift and 33's. And I have made all the proper adjustments to the speedometer and everything, somethings up with my truck