From 18mpg to 16mpg after Seafoam, Undercover, and New Tires?

if the new tires have a more aggressive tread, the actual measurements can be bigger...

on a side note, i would kill to get 16mpg... i think im at about 13mpg right now... haha

 

I would also pull the easiest plug to get to and just see what it looks like

 

I checked out this link - http://www.4runners.org/writeups/sparkplugs/.

Which Spark plug is the easiest to check? I will try to pull it tonight. If they are bad does everyone just replace with factory plugs or are there some aftermarket ones that are superior?

 

Passenger side, farthest back.

 

I wouldn't think it was the seafoam or the spark plugs unless you notice a difference in how smooth it's running. With even one fouled plug you are going to experience a noticable amount of skipping or roughness.

I have to agree with either the different tires or a change in aerodynamics to suddenly drop 2 mpg without experiencing any other driveability problems from the engine.

 

Can I get to that one without removing the air intake system?

 

I looked at it at lunch. That one does look pretty easy to get to. Do I need to worry about putting Anti-seize on the threads and dielectric grease in the spark plug boot if I am just removing and putting right back in?

I checked my service records and Toyota changed my plugs at 31k and 61k. I am at 84k now.

 

what kind of mileage difference did they notice with an empty bed vs a camper shell?

 

To the OP, I would put more air in the tires and run down 2 or 3 tanks of gas to get a consistent mpg reading over a longer period of time. How much city driving do you do?

 

I can't get past Arrow Dynamic!

 

I basically got new tires, did seafoam, and the put the CL find of the tonneau cover on in the same week. I did not take the time to get a reading.

I put a fresh tank of 93 octane of Chevron (normally run 87) I added chevron with techron engine cleaner and I put the tires to 39 from 34psi. I basically do all city driving. A lot of stop and go in Dallas. I was doing all city driving before also.

I guess the frustrating thing is I went from A/T tires to more of a street tire and mileage got worse. I like the A/T look better, but for better mileage and a softer ride, I got rid of the looks. I got softer ride, but lost mileage so far.

 

I don't think they did a camper shell.

 

well, if you do all city stop and go driving, I doubt any aerodynamic changes from the tonneau cover would have an effect. If your driving at highway speeds, sure, but not in the city. Also can't see a 2 mpg decrease for every 55 lbs added to the truck. Change your oil and fuel filter. If it is still low, chalk it up to the new tires.

 

I pulled a plug tonight. Does it look like it needs to be changed?

 

Looks pretty good to me. Make sure to check the gap.

While you have your intake off I would go ahead and clean the throttle body, or atleast look in there to see if there is a lot of build up.

 

I didn't pull the intake. I was able to get the one plug on passengers side closest to the cabin without removing anything else. I haven't decided if I want to tackle the throttle body myself yet.

 

I was in the same boat as you, a little unsure if it was something I wanted to do by myself, especially since its an integral part in making sure our trucks run. However, its easier than it looks I promise. 3 bolts to take off the intake, 4 bolts and some hoses to remove the throttle body, and unhooking the throttle cable which comes right off.

If you are unsure, start with taking the intake off and just doing a visual inspection of the butter fly inside the throttle body.

Feel free to PM with any questions, as this is still pretty fresh in my mind since I did it last weekend.

 

I may give it a try. Everything went right back on pretty easy? I thought there was a how to link with what to use and pictures somewhere? I haven't found it yet.

Was your throttle body really dirty? Did it make a difference in performance?

 

Yeah its just a matter of putting hoses back on and bolts back where they came from. I marked some hoses just to make absolutely sure that I didn't mix them up.

link

 

Intersting? Now that you mention it, about the time I switched strictly to Chevron, I have got worse mileage. I never considered the gas being the problem (or part of). I don't remember the exact times, but about the time I switched a year and a half ago, my mileage decreased and it has continued to get worse.

Can anyone prove or enlighten on the subject?