Extended Fuel tank for a F100? (1 Viewer)

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Joined
Apr 18, 2005
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Location
Idaho
I know that there are options for the extended fuel tank for the older LC but I wanted to get one for my 2000 LC. I live in Idaho and there is allot of land between gas stations... And at 13 MPG it gets old... My Second question is.... Do you know of any way to get better gas mileage out of the LC's?

Thanks in advance for all the help.
Adam
 
More information on your vehicle would help, including modifications and miles.

13mpg for an otherwise stock 100 series seems a little low. Maybe a tune up, inlduding plugs and wires?
 
The Truck is stock! I put a K&N Air filter is all. It has 75K miles and runs great. Do you think plugs and wires and a tune up?
 
I get between 16 and 18 mpg every tank full... checked last 10 tanks.. 98 LC..

75K miles..
 
Yeah, you are nearing the end of the plug life if they've never been changed. Go with OEM Denso or NGK plugs. You probably don't need to change the wires at that age and miles.

Might also try replacing your diff and transfer case fluid with synthetic, or at least change it period if it's never been done.

People have been mixed on the K&N filter on here, and by "mixed" I mean they either don't like it or they hate it.
 
shocker said:
Yeah, you are nearing the end of the plug life if they've never been changed. Go with OEM Denso or NGK plugs. You probably don't need to change the wires at that age and miles.

That's incorrect. The 100 series has irridium plugs, with a scheduled change interval of 120,000 miles. I know that they could, theoretically, be less efficient than new, but it's unlikely.
 
hank14 said:
That's incorrect. The 100 series has irridium plugs, with a scheduled change interval of 120,000 miles. I know that they could, theoretically, be less efficient than new, but it's unlikely.

Well, to get 13mpg as opposed to the 16-18 most others get, something is different. And the spark plugs are one of the most likely culprits. Behind sticking brakes or a lead foot.

I know the plugs are supposed to last 120K, but it's a direction I told him to look as it's certainly probable that they may need replacing now. I've personally have never gone 120K miles without them looking questionable.
 
So how fast do you drive, Bullseye?

How long have you had the truck?

When did you see the mileage drop, or has it always been that way?

What fuel do you run?

There are many factors involved here. I'm certainly open to criticism. :eek:

The plugs are one of how many components which can and will affect performance? Inspect them, measure the resistance of your wires, but don't replace them without a better reason than that, IMO.

I have seen a dirty MAF sensor and throttle body that affected the way my truck ran- it had a K&N when I got it, but does not anymore. I cleaned everything up, and now it runs great. You might check the threads about K&N filters as well.
 
The plugs on the 98-2000 are 90K intervalk and after 2000 they are 120K. The LC and LX however do not have a cap, rotor, or wires they have coil packs which have no interval. I do not think that 13mpg is that bad. What does the window sticker say that it shoud be?
 
What type/size of tires do you have and what pressure is in them? FYI: Living at 4,500 feet my '99 100 gets minimum of 14 and high of 15 with 285R75 16 GY MT/R at 35psi for city/highway mix. Of course off-road I get less...

This is with new air filter (stock), Bosch plugs, Amzoil everywhere. FYI: At 70k my factory plugs (probably the originals) were a little worn looking...and after installing the Bosch plugs the engine started more promptly, has a little more power... FYI: With the stock Michelins I got about 1mpg higher.
 
Seems everyone has covered just about all the ways to increase fuel economy:
1) tune up: Denso plugs, OEM air filter
2) synthetic liquids: I've been using Delvac 1 5w40 and Rotella T synthetic 5w40 in both my honda and toyota. I once tried switching to M1 10w30, but it dragged my fuel economy DOWN by 1.5mpg (so I got the same as with cheapo valvoline 10w40 dino).
3) slow down: This includes when accelerating at the green light, also coasting to a stop at the red helps conserve fuel and saves brakes. Most cars get their best mileage around 50-55mpg. Slowing down on the freeway by 5-10mph can save upwards of 20% on fuel.
4) A spare fuel tank will add weight, decreasing mileage. Figure the tank weighs around 50 lbs empty, then 15 gal of fuel @ 6 lbs/gallon is 140 lbs, about the weight of a passenger (but at the rear of the vehicle).
5) Oh, almost forgot...run good quality gas...Chevron, Shell, etc, not el cheapo junk gas, and use the recommended octane.


The only way to significantly boost fuel economy is to install a 1HD-FTE turbo diesel like the overseas HDJ100's (similar power as the V8, but 24mpg). I imagine the '03 100 series w/ 5spd auto might give slightly better economy over the 4spd. Can anyone confirm this?
 
hank14 said:
Your first question was about the extra gas tank, Hank14 is correct with his link to Man-a-fre.

Here is a link with alot of info on aux tanks, both 80 and 100. There are also links inside to a site that has great pics of 80 and 100 series tanks to show you the differance. Contact Steve-O if you really are interested in a tank.
https://forum.ih8mud.com/showthread.php?t=33931
 
Ok, wow I love this forum!!! All good information.. I use 91-92 octane and only from good gas stations.. I do notice it takes a few seconds to start the vehicle weather cold or hot (So I am thinking plugs might be a good idea) my wife drives it most of the time so no heavy foot. When I drive it I get the same 13MPG. The tires are Toyo Off roads (but not a knobby tire at all), I live in Idaho so 2400 feet or so altitude. I changed all the fluids to synthetic (including the diff, transfer case, transmissions and engine) before I switched the K&N I got 13 MPG for 5 tanks and I get the same now. I got this LC about 7 months ago, I am not sure how many other owners there has been. I had the alignment done and I have had it checked out by two different garages. I might have a brake problem as when I put on the parking brake and then let it off I get a squeaking noise that goes away after 5 miles or so.
 
bsjoiner said:
The plugs on the 98-2000 are 90K intervalk and after 2000 they are 120K. The LC and LX however do not have a cap, rotor, or wires they have coil packs which have no interval. I do not think that 13mpg is that bad. What does the window sticker say that it shoud be?

I was definitely wrong about the plug interval. It is 90K for 98-99, as shown here:

http://smg.toyotapartsandservice.com/guides.php

I changed mine at 116,000 and didn't notice any significant difference.
 
Now that you mention you're in Idaho (i'm thinking cold weather), I've noticed I get worse fuel economy (on both cars, a 86 4runner and 01 honda prelude) in the winter than summer (and this is Arizona, so cold winter temps around 60/35F, hot summer temps around 105/75F). My theories as to why this happens is (1) the colder weather has higher air density, so the EFI might try to force a richer mixture (ie, more fuel) vs. hot, dry summer air (little density-->leaner mixture), and (2) engines takes longer to reach operating temperature, and it's less efficient until it does so. And that's with the car garaged. If parked outside during the winter, a 3-5 min warm-up period 2x/day drags economy down another 1-2 mpg. I guess you can't do much about this other than park inside the garage at night.

Here's your ticket to 24mpg....

http://www.japanesevehicles.com/tcl/en/vehicleDetails?vehicleId=50895
 
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