CoedNaked

I would switch to synthetic Oil even if I knew there would be a leak (as long as it's minor). I would say if I lost 2 quarts of oil between oil changes (say every 3500 miles), that would be acceptable enough for me to use synthetic oil compared to say if I was losing hardly anything with dino oil). The gas mileage improvement from Synthetic might pay for the quarts you go through, and the fact your truck is running synthetic which helps it run cooler (which promotes less warpage of critical parts like your head gasket), improves gas mileage slightly, improves power very mildly, and it overall runs like it's new without being gummed up, is enough reason for me to switch even if I was losing that much. Now if I was losing more oil than 2 quarts per oil change then it's time for a ring job or a short block rebuild. If you're losing that much oil per oil change, then how much fuel is also getting by into your crankcase as well? You could be destroying your oil's (synthetic or otherwise) ability to do it's job by having fuel mixed with it.

Switching all my drive train (front/rear diff, tranny, x-fer case) over to synthetic is on my next to-do list when the time is up. That will help mileage, power, and promote durability as well. I'm switching all my drive train over to Amsoil fluids - gonna keep the oil with Mobil 1 since I've always used it.

Fo by Fo

Thats very interesting, my 91 with the v6 is at 3k rpms or so at highway cruising speeds. I've thought it was strange that at cruising speeds the rpms are at the point I usually shift. It seems like it needs a 6th gear, hahaha. Or just more power.

But about the gas mileage question. Everyones suggestions are great. But another suggestion is driving habbits. I'm sure you already knew that but thought I'd throw it in anyhow. I feel your pain on the gas mileage thing, espcially cause my last vehicle got at least 25 mpg. But thats part of owning a truck/suv

noodle

I don't know much about 2nd gens but what about Cleaning the MAF sensor?

86 TurboSR5

I get 33+ highway. 36 lbs in tires with x cab and camper plus 400 lbs in back. 5 speed turbo 62 mph. 48 on engine but I have only a 4 cyl engine. but this truck flys.

PoleVaulter95

wow your guys are making great mileage im pushing 13.5 (all my driving is around town) and i baby this thing i have 32's on it and the isr mod but i still only make 13.5 mpg last year i had a new cap, rotor plugs and wires put in and i know my airfilter is clean. anymore suggestions?

YotaND

^^^ Any words on this? After this post the thread went to synth vs. dino.

regularguy412

MAF = VAFM on 2nd Gens. They do the same thing, but in different ways. MAF uses an element to sense the volume of air flow. Our VAFM uses a spring-loaded flapper door. As it gets pushed open farther by faster airflow, the door rotating on its pivot turns that rotation into a digital signal and sends it to the ECM.

When I lubed mine, I just wiped the interior of the VAFM body down with a soft cloth and then used a very small amount of SPL 100 Lube on the hinge of the door. You can't really 'see' the hinge itself, but you can see where the door rotates on the body. A small spritz of lube in the right place and you're done. Don't let the lube get up into the electronics area on the top of the VAFM body.

If you're sure its the VAFM clicking, it could be stuck. The door in the VAFM is spring-loaded. I suppose it's possible that the return spring broke, but I've never heard of one doing that.

The over-fill was likely to compensate for the drip. An over-filled crankcase 'can' have a small negative effect on MPG, but it's more likely to cause premature engine wear. If the oil is too full, the counterweights and rod journals splash into it as the crankshaft turns. All this splashing when the engine revs causes the oil to foam. Oil that has turned to foam won't get sucked up by the oil pump. You can see where this is going. Just drain it down to the FULL mark and keep vigilant on leakage. When it gets down to the LOW mark, fill it back up.

Mike in AR

seanathan

well i dont know about all of yall but i am getting about 12.7 with alot of it being highway i am going to try a few things like the manual hubs in the front and maybe something to the air filter i started running mid grade and a new fuel filter to get where i am now before i was at about 11.3 so i have gained almost a mile and a half so if there are any cheap improvements for a 3.0 4runner auto plz pm me


also when i start mine i smell gas expecialy if i start it and pop the hood to look under it is that normal or could i have a leak?? i have looked but i dont see one

rentedmule

When I was having trouble with my O2 sensor I thought I could also smell gas when I started it. If your O2 sensor is bad it will run rich and kill your MPG. I wasn't sure if it was my imagination or not but I never noticed it after I fixed the sensor.

Elton

wow that sucks are you running bigger tires than stock ?

YotaND

How long does it take you to start your engine. Mine did the same and it turned out to be the screw backing out of the fule pressure dampner. It took a long time to start and smelled of gas. i tightened the screw on the back of the dampner and now the truck starts right away with no smell of gas. Feel for the knob like thing at the back side of the right fuel rail. Its hidden by the plenem so you will have to work by touch. See if its wet when the moter is running or just turned off.

wishmaster22

I have changed the plugs, wires,and rotor cap. I noticed a big difference at first. I have a 188k on a 94 4x4 4 runner. Then I changed my fuel filter, all was well. Then a week later my wife had my car for about 5 days and noticed it was running slow. Checked the oil was low, added oil, started running better. Now a week later with full oil, it has no pickup and getting 14 mpg. Right after the tuneup it was about 17mpg. I don't know how to check or adjust the timing, could this be causing a lack of acceleration and poor gas mileage? Or is it just that I have 188k miles on it and its old?

Really would like to get some acceleration, any ideas on how?