Gasoline Consumption

I have a '95 Toyota 4-runner with a 3.0 engine. It is giving me 15 m.p.g. with little hiway travel, some rough dirt roads, some 4X4 and rural traffic. All mileage is put in under or at the speed limit. Can I do better than this? I owned a Buick Century Wagon up until last November when some bozo in a big truck rear ended and totalled it. The Century was giving me 22 or more m.p.g. and it had the same sized engine and was of the same year. In fact, my Toyota engine was recently rebuilt. When they did this they didn't replace the wires and I assume they did replace the plugs. Otherwise, I've made sure it has been tuned properly. I also keep the tires correctly inflated. Should I expect better mileage? Can I do something else to improve it? I know that I'm not alone in this quest.

Reply to
LackofWind
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With the variety of uses you described, you're probably doing as well as you can. I have a 2002 4x4 Tacoma with 3.4L 6 cyl engine. With mixed driving like you've described, I get 15-17 mpg. If you want to know whether your engine's tuned as well as it can be, the only accurate method is to fill up the tank and take a trip at highway speeds, with as little "city driving" as possible. Even better, do this 4-5 times and average the results.

Reply to
JoeSpareBedroom

A thinner synthetic gear oil helps, Mobil, maybe, or Royal purple. Synthetic in trans, motor-5-30, differentials and transfer case might get you 3 mpg. Check timing, retarded timing lost me 3-4 mpg in a 4 cil, even try advancing it 1/2-1 degree, but if it knocks go back. A bad O2 sensor, sticking brakes, bad plug wires, a dirty rotor and cap if you have one reduce mpg. Lower rolling resistance tires help. 4 runner tires are big and heavy, there are alternatives

Reply to
ransley

Try hypermiling.. Google it..

Reply to
in2-dadark

I didn't realize that Buick Century Wagons offered 4X4. Using 4WD will have an adverse effect on fuel economy, and all things being equal, a heavier vehicle with a full frame will use more fuel than a lighter vehicle with unibody construction.

How did you make sure that the engine has been tuned properly?

What kind of spark plugs are installed? What is the resistance of the high tension ignition wires? Is spark timing advancing properly? What size tires and wheels are installed? What is manifold vacuum at idle and at 2,000 RPM? What is the condition of the ATF?

Reply to
Ray O

I put free wheel lockouts on a 4wd Blazer years ago, and I noticed 0 mpg increase, maybe a 4 runner is different

Reply to
ransley

Reply to
LackofWind

What is the resistance of the high tension ignition wires? Is spark timing advancing properly? What size tires and wheels are installed? What is manifold vacuum at idle and at 2,000 RPM? What is the condition of the ATF?

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Reply to
LackofWind

e quoted text -

Platinum only last longer

Reply to
ransley

quoted text -

O.K., I'm trying to come up with a list of items to buy at AutoZone to improve my mileage. This is my thread i.e. my vehicle. How about an oxygen sensor? Are they expensive? I want to keep it as close to being over $20 as I can. Is there an easy way to find out if the one in my car is bad? How about Platinum 3 two pronged plugs? Will the better burn in the gasoline warrant the purchase of $16 or $17?

Reply to
Windsurfer

I posted the laundry list of questions and things to check. In my experience, changing parts in hopes of fixing a problem, whether it is poor fuel economy, poor performance, or a drivability problem, rarely works and the parts changer ends up wasting money.

The correct way to solve the problem, if there is one, is to check parts or settings before messing with them. Most electrical and electronic parts can be checked with a volt/ohm meter, and you can get one that will work for automotive use for under $40. That investment will pay for itself many times over because you can check parts before replacing them unnecessarily.

The "best" spark plugs from the standpoint of likelihood of working are OEM Denso or NGK plugs that are specified for your engine. Other spark plugs are a hit-or-miss deal, and they may or may not work well and last long. IMO, the same is true for all ignition parts and electronic components.

Changing spark plugs, ignition wires, and the oxygen sensor may or may not improve your fuel economy, so I posted that list of questions to narrow down the list of things that may work for you.

One of the things I didn't mention in my original list was to check tire inflation pressure. Inflate the tires to 5 or 6 PSI over the recommended tire inflation pressures listed in your owner's manual or on the driver's door frame or on the glove box lid. While you are at it, check to see if the tire size installed is one of the sizes listed where the tire inflation information is listed. The reason I asked about tire size is that a larger tire will rotate fewer times than a smaller tire over a given distance, so the odometer reading will be under-stated, so fuel economy will be under-stated.

Reply to
Ray O

Bad oxygen sensor or major problems will trip the Check Engine Light

- don't start changing expensive without a reason - throwing money at the car at random is foolish.

Synthetic motor oil and synthetic ATF/gear lube will only make minimal (but still measurable) improvements to fuel mileage, but the car will also last longer - so they are still worth it.

The "Super Duper" triple electrode spark plugs usually aren't worth the powder it would take to launch them into orbit. Save your money and put in the factory recommended NGK plugs. Platinums only if the factory calls for them.

The "Tornado" and other "Magical Fuel Saver" gadgets and additives? P.T. Barnum was right, there is a sucker born every minute - Don't be one. Detroit would kill to get their CAFE fleet fuel mileage up by a tenth of a point, and they have million-dollar testing labs to find out for sure. If these devices actually worked as touted they would be sold to the car makers by the millions and factory installed.

You get better results by getting your lead foot off the floor. Any "miraculous gains" after installing one of these placebo devices are just from you driving a bit more sensibly.

Plug wires, cap and rotor should be done if they are still the originals, and replace with factory parts. You will read high resistance on even good plug wires with an ohmmeter, the core is carbon impregnated fibers for radio interference suppression. When they go bad the resistance goes even higher.

Check that you have proper lower rolling resistance tires, not the super-sticky racing gumballs (UTQG Treadwear ratings at 100 or below) or the "Loss Leader" $29 Each! tires that are sold to the kiddies...

And on a 4-Runner they might have put on 33" bias ply SuperSwampers and jacked the suspension up 6", both of which are very bad for rolling and wind resistance and therefore fuel mileage. If they haven't changed out the rear-end gear ratios to where you're stuck using big tires, go back to a stock (or close to) tire size and take out (most of) the lift kit. Jacked up is bad for safety too - the higher you are, the easier it falls over. Over 2-3" is wasted, over 8" is asking for trouble.

Tires inflated right, and aligned right - bad alignment will suck up a lot of fuel, and will be very visible in excessive tire wear. Has the car ever been in a big wreck?

Check for dragging brakes, bad wheel bearings, and the like.

Get the excess weight out of the car. You need to carry a basic emergency hand tool kit, a first aid kit, a fire extinguisher, 6-10 road flares and a few bottles of water - but NOT your entire rollaway, a medical kit that puts an ambulance to shame (unless you are also a Paramedic) and a "Donner Party" sized six months worth of provisions.

Keep all the crap off the roof rack to cut wind resistance. If you aren't going kayaking this weekend, take off the kayak and rack.

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Reply to
Bruce L. Bergman

Check and replace your air filter as required. You have mentioned driving on dirt roads.

Reply to
EdV

Yeah, and considering there may be blade flex with the 'Tornado', about the last thing I want is a metal fan blade flying around my air intake...

Reply to
Hachiroku

be checked with a volt/ohm meter, and you can get one that will work for automotive use for under $40. That investment will pay for itself many times over because you can check parts before replacing them unnecessarily.

Reply to
Windsurfer

Just to let you know that I use both handles and this is me. I put the cruise control on with the Buick at 58 m.p.h. Around town, I'll see 19 m.p.h. with the A.C. Although I'ld love to take the 4-runner out to Colorado or trailer a small sailboat sometime, I only use it to access Windsurfing beaches, package pick-ups and dump runs currently. Thanks for all your posts, though. I have read and copied them for futher reference

Reply to
Back Roader

Brucie, the next time you go to the Falmouth dump.... leave all your windsurfing gear. Leave your computer. Leave your Toyota. Leave yourself.

Reply to
oneup.again

Measure spark plug wire resistance with the engine off -it will hurt with the engine on :-)

Happy motoring!

Reply to
Ray O

O.K. I will go thru with it when I get the chance.

Reply to
Back Roader

Although you are more than likely posting the truth i.e. that overinflating your tires by 5 or 5 PSI will increase your miles per gallon. I found this in the LeSabre owner's manual. NOTICE: Don't let anyone tell you that underinflation or overinflation is all right. It's not.

Reply to
Windsurfer

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