Home Forums Gear Hunting Trucks and Four-Wheel Drives Fuel saving tips on gas engines please.

Maybe some guys with later pickups with instant mileage readouts can offer advice here. Let's assume a fuel injected gas engine, towing up a very long moderate grade...which would give the best mileage? Using a lower gear, higher rpms, but lighter throttle position...or...highest gear that can be pulled, lower rpms, full or near full open throttle.

Generally the former. Especially if it's turbocharged. Better for the engine, too.

My Dear old Granny said "put an egg in the sun for a week, then put it between your bare foot and the accelerator pedal " You will be surprised how much more fuel mileage you can get !

I thought this was going to be one of those cow magnets things where you put them an the gas line. Anyone remember that ?

No idea how the instant read things work, but they replicated a vacuum gauge.
You want to maintain fairly high vacuum.
My car has the digital thing, it's amazing how you can go up a hill burning 5 bars
worth of fuel. Lift your foot very slightly, and fuel consumption drops significantly.
With little to no reduction in speed. The opposite is true. You can press down just
a bit, increase consumption, and see little to no speed increase.

Ever drive an old car with vacuum wipers.
Drive like it's pouring, and you don't want the wipers to quit!😂

If you want good mileage, turn off cruise control unless you are in level country.

Former - you're letting the gears do the work instead of just dumping more fuel into the equation.

I shift down and let it drink. Towing my #3500 boat in the mountains my 4.6 tundra gets 13-14 mpg. I leave it 4th (no overdrive) when towing always unless pulling a hill and then I manually shift to 3rd and let it rev until I get to a flat or downhill.

I’m actually surprised it does so well locked out of OD gears when towing. Its better on fuel than my old tacoma did towing my boat.

Also, I record the mileage each tank so I’m not spitballing on the mpg figure while towing. The real trick though, keep it 65mph or less. Less fuel…. and way safer.

https://www.fuelly.com/car/toyota/tundra/2019/bigbadheadwound/882472

My 2019 6.2 F250 makes better mileage with the cruise on 55 or 75 than it does at 65. I guess the 3.73 rear end puts it in the wrong RPM range at 65, which sucks because that’s the speed limit 90 percent of the roads I drive. At 55 it’s just loping along and at 75 it doesn’t shift as much on hills.

My wife's Camry was claiming up to 80mpg on I-80 going across Pennsylvania, then we'd get to the bottom of the hill and start going Up the next hill, and it would drop back to 33mpg. It was quite interesting to watch the ticker swapping ends. That was with the cruise control sitting on about 73 or thereabouts. 2.5 liter 4 banger, still runs like a wild deer, though.

My little pickup has a 4liter V-6, and just running around here locally in fairly hilly Kentucky terrain, I'm lucky to squeak out 19mpg running at 60-65. I think I might as well drive a full-sized pickup, and be more comfortable.

My new 5.3 crew cab 4x4 trailboss has gotten 25 mph on a trip. Towing my 8500 lbs trailer I was getting 10 mpg or so if I remember right. From a power standpoint I could hardly tell it was back there.

Without me adding to what's already been said and duplicating. I would like to add, that I'm a maintenance, and pre-maintenace Freak.
With that being said, keeping your unit in the best possible running condition, and Using Lucas Fuel Injector Cleaner, per measured applications, have helped me a lot over the years.
I have noticed the difference using it since my Mechanic suggested it about 15 plus years ago. One gallon usually last me a couple years, and at about $32.00 Bucks a gallon, to me it's well worth it!

HS58

Only drive downhill

I stated my OP question poorly, let's try a hypothetical situation. Ok, we have a small 4 liter fuel injected gas engine, a 6 speed manual, a 4,000# towed load, a modest 6% average grade, the course is 5 miles to the top (this happens to match the grade to Siskiyou Summit on I-5 northbound). Which scenario will result in the least total fuel consumed to the summit, 3rd gear high revs, partial throttle, or 4th gear low revs mostly wide open throttle?

3rd

I don't know why a WOT condition would burn less fuel than less than WOT over the same distance/time.

Teal, I'm no math guy, clueless actually, and I'm not arguing at all...but there is the fact that the exhaust readings from the O2 sensors don't let modern fuel/air computer engines receive an over rich mixture for clean combustion in a "lug" load condition. So, at a lower total rpm "lug' condition over the 5 mile course...there will be less total cubic displacement volume going thru the engine.
Now when the truck is dropped a gear, and revs are increased to maintain road speed, and less than wide open throttle...the total displacement volume consumed will mathematically be higher...so my question is, (assuming the fuel/air computer always strives for 14.7 to 1, air to fuel) won't the more rpms (complete 4 stroke combustion cycles) require more fuel than the lower rpm ''lug'' condition? I was hoping someone with an on dash fuel readout could answer this.

I would look at the rpm powder and torque curve for your particular engine. Every engine has a sweet spot where it is running the most efficiently. My newer truck is rated 150 hp more than my old truck yet gets better milage because it isn’t lugging at lower rpm’s. That old 302/5L V8 was great in a Mustang, but it had no place in a heavier F150 4x4 with a 5 speed. It made power but only at higher rpm than where it spent most of it’s lifetime.

Driving for the best MPG

I have a newer 2021 Japanese 4X4 with a V-6. It has a fuel mileage screen with average MPG since last fill up, and a real time bar graph showing current MPG second by second.
I have found that if I try to maximize my fuel economy, I can increase my MPG 2 to 3 MPG.
With current gas prices that works out to about $15-, or 60-miles savings per tank.

The most important thing is to focus on minimum throttle pressure.

When your vehicle is moving at any speed, that is momentum. It takes a lot more energy (gas) to obtain momentum (accelerate) than it does to maintain momentum (cruise).
It takes a lot less energy (gas) to obtain momentum slowly that it takes to obtain momentum quickly.
When accelerating from a stop, or merging into faster traffic, use the minimum throttle necessary to achieve the desired speed.
When cruising on a throughfare or freeway, back off the throttle as much as you can while still maintaining a reasonable speed.

In other words, drive like your grandmother.

Keep tires inflated to the higher end of their recommended range

Air filter with more flow

Wind deflector on bottom side of front bumper

Drop tailgate



All things I’ve heard before. I know number 1 and 3 work. Not sure about the other two

As for your truck question specifically. Why don’t you post that to the YouTube channel “ tfl trucks” Facebook or something. They test this stuff and post videos about the results. Maybe they can do a video or have one that answers the ?