Mpg seems very low

[unko]

I'm was reading speedys garage on the deck plate mod, and it net him a 5-8 hp gain and it's so simple that I want to try and get it done ASAP. I have the technical skills to do it, I just need to borrow a friends drill. That with the ISR mod I feel should have a significant difference in power as well as mpg. Both of those are fairly easy and cheap to pull off. I think a muffler is next after I get those out the way.

First things first thou, I need a good alarm with remote start, toyotas in Hawaii Oahu especially have been getting stolen a lot lately.
death to all thieves!!!!

 

[tyr0981]

I get 200 miles on full tank. Maybe little more. Is replacing the o2 closes to the front easy ? Why only front one and not one under the car near muffler ?

same boat.... i think i still have the OEM O2 sensor in there also... I've cleaned everything else i can think of, replaced fluids, wires, plugs, filters.... so i guess this is the last thing on the list! lol 256k miles on the O2 sensor isn't too much right? lol

 

[fblainen11]

My 2wd 97 with oversized tires averages 20mpg. 23 on hwy and 17 in city.
I was shocked that it was that good. I drive it pretty easy.
She's old afterall....though I'd never say that in front of her.

 

[unko]

I went and put gas last night and I check my tires pressure after. All four tires were at 20psi. So I inflated all of them to the max psi on the tires, is what I did correct or should I be inflating them to the psi rating on the door jam of the vehicle.

The max psi on the tires were 44 I went to 40 but on the door jam it's rated at 29.
Hopefully that was the reason of my bad mpg.

 

[Crashnrondo]

It depends on the tire but I would start around 32-33 PSI, 20 PSI will hurt the MPG's for sure

 

[piecesparts]

Max pressure is the recommended pressure for the load rating on the side of the tire. I run my tires around 35 to 37 pounds cold air pressure and after driving for awhile that pressure will increase to around 40 to 43 pounds. The 20 pounds that you had was killing your gas mileage and the tires, not to mention putting you in a place where an accident could happen. Remember the issues a few years ago with the Firestone tires and the Ford Explorers. That was primarily due to people not keeping their tires inflated to a good pressure, not the tire or the vehicle's fault. However, just keep in mind the Toyota 4 Runner is a tall thin vehicle like the explorer, so treat it appropriately.

 

[Nunyabiz]

I went and put gas last night and I check my tires pressure after. All four tires were at 20psi. So I inflated all of them to the max psi on the tires, is what I did correct or should I be inflating them to the psi rating on the door jam of the vehicle.

The max psi on the tires were 44 I went to 40 but on the door jam it's rated at 29.
Hopefully that was the reason of my bad mpg.

Yeah that would do it for sure.
What is on the door is just for the STOCK tires that came on it.

My tires are rated at 44# pressure and that is what I run them at and I use Nitrogen so they stay at 44# longer with less fluctuation.

 

[unko]

Max pressure is the recommended pressure for the load rating on the side of the tire. I run my tires around 35 to 37 pounds cold air pressure and after driving for awhile that pressure will increase to around 40 to 43 pounds. The 20 pounds that you had was killing your gas mileage and the tires, not to mention putting you in a place where an accident could happen. Remember the issues a few years ago with the Firestone tires and the Ford Explorers. That was primarily due to people not keeping their tires inflated to a good pressure, not the tire or the vehicle's fault. However, just keep in mind the Toyota 4 Runner is a tall thin vehicle like the explorer, so treat it appropriately.

I remember that issue with the explorers, part of it was that the tires were rated for a certain capacity and the explorers exceeded them.

I really feel the low tire pressure was killing my gas, been driving it for the past two days with a significant increase in mileage before ever passing the half tank mark.

For all you guys out there that are experience bad mpg, don't over look the simple and obvious things such as tire pressure, I looked at my tires and they looked totally fine till I finally actually checked them. And wallah better gas mileage.

RUN THE CORRECT TIRE PRESSURE.

 

[unko]

Father's Day gift
Looks like I'll be doing the deck plate mod soon and as well as building my raised garden.
Super great deal at Home Depot, a $350 value for $179 can't go wrong with that.

Happy Father's Day to all you rad dads out there!!!

 

[kolelt]

I have a 97 with an automatic and 4WD behind a 3400 engine. The engine just got new plugs and wires with a deck plate mod tot he air intake housing and a Magnaflow muffler on the stock exhaust pipe.

Yea I dont know how you getting 200miles and have a half a tank. I drive everyday 50-70 miles usually 60-70 mph. It's lifted with 33" tires but the tires are rated heavy duty. They are heavy as shit. I see people here usually average 15-18 mpg. So I don't think there's anything wrong with my engine. Engine is low milage. New front ans rear seals, new plugs and wires, oil changes every 3k, new water pump with belt new belts. New coolant. No codes !!!! Although I haven't cleaned my MAF. I really highly doubt something is wrong with my engine or something.

It could be that the fuel gauge is little of ..... Anyone know how many miles you can drive when gas light comes on?

O2 sensors aren't crazy expensive, find one on amazon or eBay. Make sure you.get right one. If you live in CA it's different o2 then if you don't.