Fuel Economy

Does Toyota specify an optional “hot” thermostat? That might make a small difference.
The thinner gear oil should help a little too.

@badbearing
You’re puting words in my mouth. Said no such thing as you claim. Just asking a question. .

What your saying is when a vehicle was made it was made to perform at maximum fuel economy with no room for improvement.

I dont think so…

Marginal room for improvement at best. Manufacturers have to meet their Cafe’ numbers. They spend MILLIONS of dollars every year doing so. If there was a cheap aftermarket device to improve gas mileage every manufacturer in the world would be using it.

Mikey. It was made in 1989

Mikey. It was made in 1989

Obviously you don’t know it…So I’ll tell you…Cafe’ standard started in the 70’s. By 1989 4wd trucks had to meet a minimum of 19mph combined highway and city driving.

There are actually 2 questions…

#1 Can you significantly increase gas mileage in a vehicle? Answer - Maybe.

#2 Can you significantly increase gas mileage in a vehicle that’s cost effective? Answer - NO. Any thing you can do that’s going to increase gas mileage significantly is going to cost you. So any savings you get in MPG will be lost in the upfront cost.

Mike

Obviously you dont understand that what im saying is there has been a lot of technology since 1989

“Any thing you can do that’s going to increase gas mileage significantly is going to cost you. So any savings you get in MPG will be lost in the upfront cost”

Im not sure im buying that. 1/2 mpg multiplied by 200,000???

Im not sure im buying that. 1/2 mpg multiplied by 200,000???

You have a vehicle that’s 26 years old…and you’re going to get another 200k miles out of it??

1/2mpg is NOT a significant mpg increase. Will it save you money over 200k miles?? - MAYBE - if you made that change back around 1990. Small incremental changes for not too much money are possible - but don’t expect anything more then 1/2 mpg increase. 2-3mpg or more is going to cost you money.

The vehicle has a fresh engine so 200,000 is a definate possibility and 1/2 mpg multiplied by 200,000 is not a maybe. Its a rock solid YES

There are countless add-ons and additives that claim to increase gas mileage, but none that actually do. The only thing you can do is be sure you don’t have a lot of junk in the trunk, keep the truck running properly, use tires without aggressive tread (unless you need them for your driving environment), keep the tire pressure to spec, and drive as if you had your newborn riding with you.

With great respect to Circuitsmith, one thing I recommend against is going out-of-spec with lubricants and engine operating controls. Any miniscule gains will come with a high cost. Gear lubes are thick for a reason, and going hot with the engine could easily manifest itself in damaging side effects, such as pinging.

Sincere best.

The vehicle has a fresh engine so 200,000 is a definate possibility and 1/2 mpg multiplied by 200,000 is not a maybe. Its a rock solid YES

REALLY? How old is the transmission…or axles…or suspension?? All those have wearable parts that may or may NOT allow you to reach another 200k miles. Don’t define how long a vehicle will last just by it’s engine. If you have 200k miles on your vehicle now…then after another 200k miles those other components will have 400k miles.

There are countless add-ons and additives that claim to increase gas mileage, but none that actually do.

The EPA has tested many of these devices. While they have find some that work…they are NOT cheap.

http://www.epa.gov/otaq/consumer/420f11036.pdf

Some of the suspension has been replaced the rest can be. Drive train ect.

I didnt just fall off the turnip truck.

Many new parts on this rig and if i want it to go another 300,000 it will

Happy Thanksgiving!

Have a Great Day!

@beabearing
Consider all of the motors made by differnt manufactures using slight, but significant variations in their ICE motors. The 89 3.0L Toyota truck I had, was significantly differnt then say, the competing truck motor in GM products. To @MikeInNh 's point. There is no way the same device could be adapted to both motors that would make a significant improvement in performance ( mileage). Now, if it were customized for that motor, maybe. But, that customization is done free of charge by the manufacturer in the next generation…the 3.4L Toyota motor.

Many mpg figures though are improved short term by two things; gearing and transmission alteration, and weight savings. So, change the gearing, rear end ratio and accept reduced performance in acceleration and towing, or tear it apart and replace steel structures with aluminum and plastic. Sound cheap ? Hardly…Or, get a girly man Prius. Toyota is coming out with direct injection for trucks. And, it may make an awd one on the RAv chassis under the Scion name. Trade for one ? Btw, if you get 20 more years out of that Truck as a daily driver, you are dreaming. That my good man will cost you more then you will want to pay…while the rest of us will be getting 35 mpg in newer trucks.

“With great respect to Circuitsmith, one thing I recommend against is going out-of-spec…”

Note that I did ask if Toyota offered a hotter thermostat. If Toyota offers it as an option it’s not really out-of-spec.
Honda had an optional thermostat for my '81 Accord. The tradeoff is slightly more MPG for slightly less power.
Some folks put in a cooler thermostat in search for more power.

This is the first I’ve ever heard of a manufacturer offering a different T-stat as an option.
I’m also having a hard time understanding how varying the operating temp within a range that would enable good operation and acceptable emissions could manifest itself as greater MPG or less power, even if one were to accept less power.

But I’m open to a learning opportunity.

IIRC the Honda thermostats were 180F vs 195F, not a big difference.
A cooler engine develops more power because the intake charge stays cooler and denser.
A hotter engine is more efficient due to basic thermodynamics.

Cold engines have a lower thermodynamic efficiency mostly because heat flows from hot to cold a lot faster than it flows from hot to warm. Every BTU of heat that escapes from the hot gasses to the cooling system is a another BTU of heat that is unavailable to convert into mechanical energy during the adiabatic expansion of those hot gasses.
It’s also why long stroke engines are making a big comeback after a long trend to going more and more oversquare. If you minimize combustion chamber surface area, you minimize heat losses and have a more efficient engine. Also, less surface area in contact with the fuel air mixture means less unburned hydrocarbons in the exhaust.

Excellent posts, guys.

My mind thinks of an “optional” T-stat as being a different available stat on the same engine. I tend not to think of a different stat on a different version of an engine as being an “option”. A different version of an engine, especially one produced for the weekend racer set, will typically include a different induction system, different sparkplug heat range, different exhaust, and various other changes such as a different bore and/or stroke, that may or may not allow/require a different operating temperature range. I tend to think of the two as being entirely different applications rather than options.

I see your point, circuitsmith, but seriously doubt if a T-stat change from that speced on a specific version of an engine would yield greater mileage, even if one were to accept reduced thermodynamic efficiency…which should actually reduce mileage rather than improve it.

@dagosa

“With that new truck that gets 35 mpg” (I dont know of any truck getting 35 mpg) comes a sizable monthly payment for the truck that the bank owns and and good insurance payment for full coverage.

My little old toy is paid for and i make a small insurance payment and when ur stuck because your afraid your going to scratch the paint im going to drive right around you and i can get another 3,000,000 miles out of this rig. These trucks are famous for a reason. 22re is said to be one of the toughest motors ever built. Were im at i still see 80s models everyday at 50 below zero. You can have your “Status Symbol Truck” enjoy those payments and inability to fix it yourself

I might add: Ive heard they are taking these trucks in on trade and crushing them. Because they dont die …