RunninInGA
New member
Ethanol content in your fuel also plays a large part in its efficiency.
Gas mileage WAY down with 265 75 16's?
- Thread starter 1985taylor1925
- Start date
I recently move from P 265/70 Firestone AT to P 256/75 Toyo At (with similar lbs) and notice a larger drop in city, but on the highway an slight increase from what I was use to.
I have a 98 Limited with the 430 gears and around 65-70 I was fine but any faster and it sank. This was from Ohio to Oklahoma and back in Nov 2011 16mpg to 19mpg depending on speed and hills. In the city I've hit 15-16 pretty common now. This was all calculated from the GPS and I agree- There's about a 3-4% difference due to the larger size tires.
I have a 98 Limited with the 430 gears and around 65-70 I was fine but any faster and it sank. This was from Ohio to Oklahoma and back in Nov 2011 16mpg to 19mpg depending on speed and hills. In the city I've hit 15-16 pretty common now. This was all calculated from the GPS and I agree- There's about a 3-4% difference due to the larger size tires.
1985taylor1925
Senior Member
I used to run Goodyear Wrangler RT/S and they were 4 ply passenger tires. These new ones are 6 ply passengers. And ya for the spedo thats what I was expecting. Theres a wheel link that calculates the speed difference, and it said with the new tires at indicated 60 im actually going 62. Heres the funny thing, I have a Garmen GPS and it is perfectly consistent with my spedo at every speed with the new tires. Spedo says 60, garmen says 60. I almost wonder if its off so before with the smaller stock tires I was actually going slower than indicated.
Im not sure, but I got the same bad mileage in WY and NE, so I can rule out that variable.
I'm getting about 18.5 MPGs (all highway in the summer...) with 285/75/16 KM2s. Perhaps you're not taking into account the fact that the slightly larger tire is throwing your odometer off a bit? Your driving habits could be affecting it as well. Lay off the skinny pedal a bit? Keep it under 2000 RPMs? Just a couple suggestions.
Winter gas could be an issue. I've noticed mine go down a bit as the winter months approached.
Above comment for the spedo. And as far as my driving style, I would be willing to bet I accelerate slower and take corners slower than 99% of the guys on the forum. I baby my truck, even more so with the bigger tires cause I knew gas mileage would go down . . . some
The last 3 tanks have all been above 21 mpg. Highway miles (65-70mph) with ethanol free gas and S/C
OP, try a small tune up. Clean the filter, TB, MAF, and reset the EFI fuse. That should help
Air filter was changed about 8k ago. I typically change it every 12k. I cleaned the TB and MAF about a year ago. Those things may help mileage some, but thing is this happened perfectly consistent with the new tires. So the other variables can kinda be eliminated. The only other thought I have is that I also changed my oil and filter within the same week of getting the new tires. But I dont see how that could contribute as I used the exact same oil and filter Ive used since I bought the truck - Mobile 1 high mileage synthetic 5w 30 and Toyota oem filter. If anything that would increase mileage
Ditto
4-Ripcord
New member
Did you reset the EFI fuse? I do it every oil change..
Find it in the fuse block and pull it out for 30 mins. After you reset it, the engine is like a blank slate, you teach it how much throttle it needs and stuff like that. It learns to run more efficiently under the conditions of the new tires.
Find it in the fuse block and pull it out for 30 mins. After you reset it, the engine is like a blank slate, you teach it how much throttle it needs and stuff like that. It learns to run more efficiently under the conditions of the new tires.
1985taylor1925
Senior Member
I'll give it a try
PitbullRescuer
New member
Taylor, any update since resetting the efi fuse?
fish0281
New member
Oddly enough, I have had almost the exact same experience. I got new Hancooks (same size as the previous tires, 265/75), drove from CO to MN in late November, and my mileage dropped significantly. Was getting 300 - 330 a tank; now I can barely hit 270.
Shortly after the trip, my CEL came on with a P0420, so I changed AF and O2 sensors - CEL problem fixed, but not the mileage.
Did the plug wires (one measured bad), cleaned the MAF and TB, and replaced the PCV valve... no improvements thus far. :dammit:
I'll have to give that fuse a try; I think I'll do that now while I'm sitting at work!
Shortly after the trip, my CEL came on with a P0420, so I changed AF and O2 sensors - CEL problem fixed, but not the mileage.
Did the plug wires (one measured bad), cleaned the MAF and TB, and replaced the PCV valve... no improvements thus far. :dammit:
I'll have to give that fuse a try; I think I'll do that now while I'm sitting at work!
PitbullRescuer
New member
It just pulls right out. There's 4 or 5 prongs on it though so it's tough.
Atreyus
New member
just pulled it out, at the cost of a bloddy thumb now lol iono how i cut myself but i did. What is suppose to happen when you pull this thing out?
1985taylor1925
Senior Member
Just saw this. No change after pulling the fuse. It has to be the tires because thats when it started. Really disapointing
1985taylor1925
Senior Member
Ya but look at your tires. Your mileage will obviously be worse
PitbullRescuer
New member
I'm averaging 14.4 and I'm 100% stock.
1985taylor1925
Senior Member
Wow. That doesnt seem right
DannyLlama
Elite Member
Sorry, side question.. Where did you take your Avatar picture and is there a way to post a bigger size?!
