Something is wrong not sure what

[SentraSE-R]

Certainly, it can be your problem. Venting your fuel out of your tank is going to waste a lot of fuel. What to do.

[cleanspeed1]

Pull the battery cable and let the computer dump. See if the code comes back. Check your gas cap too while you're at it.

[owlafaye]

Four tire alignment? This being off will eat up gas madly.
Do you advance the timing in small increments until you get optimum advance?
Tire pressure for sure. Keep it 8 - 10 lbs. above recommended.
What kind of unnecessary weight do you carry? Dump it.
Is your thermostat correct? This can easily fool you...a temp gauge slightly off can deceive you. Cheap and easy replacement.
What weight oil in the transmission? Thin it out with Marvel
What is on the inside of your exhaust pipe? Should be gray and dry.
A high flow air filter won't hurt.
Check the radiator for air flow and make sure no one has blocked areas behind the grill or underneath the car. Blocked flow in the engine compartment invites problems fuel wise.
Try 2500 rpm shifts...

I hope this helps

[graydonengineering]

Originally Posted by WVengr

Well may have found the problem. I was reading the user manual to see if there was a thing in maintenance that I had forgot. Instead I saw "Fuel: Recommended 91 RON" Since I had a 150 mile trip to make I topped off the tank with 93 octane just to see if the recommended made a difference. I filled up again when I got home 159 miles later and shattered my old mileage record

EDIT: I thought I got 32 MPG, since that's where the gas pump shut off. However this morning I noticed that the gas gauge was down a bit even though I had just driven a few miles back to my house after filling, so i filled up again this morning, this time at the same station I had used when i left, and got a little over a gallon more in, so it is looking more like 26 MPG, but still a marked improvement.

It wasn't knocking so I hadn't thought about octane, but for some reason it made a difference. Not sure why though. Further research is needed to see what octane gives me the lowest $ per mile. Not exactly sure how to do scientific testing on this without draining the whole tank though.

Higher octain is more important in the summer as the higher temps encurage pre detonation. You may be able to get away with running lower octane in the cooler months and swithcing back to high in the spring.

[G. Man]

[QUOTE=jakobnev;245225]I'd go ahead and experiment with a bit more revs while accelerating.

x2

[Crishe]

Originally Posted by graydonengineering

Higher octain is more important in the summer as the higher temps encurage pre detonation. You may be able to get away with running lower octane in the cooler months and swithcing back to high in the spring.

Oh that's great. Good observations. Can you you please tell me some more things which we have to take when hot summer is going on ?

[jkv357]

As far as Premium giving better FE than Regular - are you comparing Regular w/Ethanol to Premium without?

You should see an increase if you don't have Ethanol, and you are best off with as low of octane as necessary that doesn't contain Ethanol.

You're lucky if you can get 87 without. 91 is the only thing without in this area.

From my latest tests, my cycle (SV650n FI) gets about 5% better mileage on Premium (55 hwy) over Regular with Ethanol (53 hwy).


Jay

[Ford Man]

Backfiring? Have you checked the timing?

[Hatchtastic]

Backfiring while coasting can also indicate an air leak in the exhaust. If your exhaust manifold is cracked, it will fool the O2 sensors into making your truck run richer. If it's not quite bad enough, it will not set a system too lean code.

As for the EVAP code, check your gas cap first. Always click it, and make sure the gasket is in good shape. This code IS for a circuit problem, but it could also just mean the system is unable to maintain or achieve vacuum during the test. If your vent solenoid has failed, this does not mean you are venting to atmosphere. But, depending on how it runs the test, you could have a leak to atmosphere in the tank. Check the gas cap! You said it came on soon after you filled with premium right?

The timing actually is adjustable on your truck. If you need the procedure, PM me.