Hello my beautiful peoples, I come with a question. A question that to some may sounds silly, and to the broke (such as myself XD), a worthy question to ponder. What are the different ways that one could improve their gas mileage, be it via engine upgrades, better driving habits, or body work, etc.?
On top of that, how would one find a harmony between street-terrorizing screaming chicken, and a long road tripping road runner?... Basically, what could some one do to improve mpg and still go vroom on the highway?

Sincerely,
Lulveau.

 

Keep ones foot from being so heavy on the gas pedal

 

Indeed, truly an unexpected yet powerful piece of advice... 👏

 

For one thing I think the best thing you can start off with would be


1. Get your car to optimal fuel efficeincy that it was designed for
- plugs
-wires
-cap
-timing
-change al lfluids
-coolant temp sensor 9this increased mine tremendously)
- oxygen sensor
- air filter etc..
- thermostat

2. Lose any excess weight... im not sure how much thi woudl help but why not?
- lose any excess junk in the trunk
- switch to newer lighter rims?

3. Optomize to the best of today's standards
- Use modern fuel cleaners to clean out any gunk (kinda basically part of number 1)
- they have more fuel efficient tires these days...my camry got firestone "fuel saver" tires which I assume means it has less roll resistance etc... they seem ok

 

Other than the obvious of 'make your car as good as new', it's a fool's errand to try and turn an f-body into something it's not. You'll spend a bunch of time and money engineering solutions that won't pay you back in fuel costs saved. The unexciting but practical answer is to buy a Honda Civic HF, a hybrid, or similar newer vehicle that benefits from decades of efficiency innovation and be done with it, if fuel economy is truly a concern.

 

To further what others have posted above, another area that would make a difference would be rear end gearing. Rather than going super short, try to find a nice balance, somewhere around 3.23-3.42. The best thing I did for my gas mileage was lose weight on the car. The LS1/ 6 Speed swap helped out as well, but I'm not advocating for that in this thread.

 

Third gens do make a good platform for efficiency with the low drag coefficient. A TBI 305 with a five speed manual will do near 30 mpg with an egg under the gas pedal. But real performance with high economy would be hard to get with the old small block. My L98, mostly stock, 3:23 rear, high flow cat and headers will do 23 mpg, run on regular gas up to half throttle or so.

 

If you want better fuel economy and more power, then you have to build your engine to extract more power from every drop of fuel. You use less fuel to make the power you need to toodle down the road. And you can make more power from the fuel you use.

Basically it means putting $$$$ into extremely good cylinder heads. The LS engine is light years ahead in this category.

 

Sounds like a partial plan my man... any particular year bird then I should look for? I've been spying an 83, but after reading all of the responses I'm still a little open to suggestion.

Or a 300 Hellcat... 😐🙃

 

LS has better heads which helps make top-end power but the real mileage improvement came from engine management. I have had both 350 and LS powered trucks and vans and the small blocks hold their own. My stock 5.7L Vortec express van got better mileage than my 2002 5.3L 1500 truck. I did not keep the truck long because the 5.3L was a dog.

 

Surprised nobody's mentioned tires yet. Make sure your tires are aired up to spec, and check them when the weather changes (colder temperatures = reduced tire pressure). Underinflated tires can cause a noticeable reduction in fuel economy.

If you want to go to extreme lengths, you can use a harder, narrower tire with less aggressive tread on a suitable rim (all contributing to less rolling resistance). You can also bump up the air pressure of your tires beyond the recommended spec. However, this changes will impact how the car handles and may lead to safety issues (smaller contact patch = less traction in corners and on acceleration and braking). Plus, the cost of different tires + rims will probably eat up any savings realized by improved fuel economy.

Edit: whoops, missed the last item in 1989karr's list

 

My old 94 350- TBI Silverado extended cab got better on gas than my single cab 5.3 GMC pickup. 21mpg vs 15mpg. My Thirdgen with 350 TBI gets up to 23mpg highway and that's with 3.73 gears. Good running engines get better mileage

 

Not sure what is considered acceptable on these two fronts but I've managed a mid 12 second ride that knocks down over 20 MPG (US) on the highway. The highway tune was spot on but the ET had room for improvement without any sacrifice to the former.

Seems reasonable enough. And that's with a carburetored gen 1 355.

I support of the LS platform, we've also got a 10.9x Chevelle with an LSX 454. It too can knock down the same MPG. Maybe even a couple points better. That's throttle body EFI.

 

With a 383 TPI my old G20 van would get 21 mpg on roadtrips with the a/c blasting and still knocked off a 13.9 @ 101 mph pass at 5,300 lbs with a 3.07 rear gear and street tires. The 305 before the 383 ran a 14.9@ 96 and would get 23 mpg highway.

My buddies LQ4/4L80E/4.10 geared Chevelle knocks on 30 mpg highway. However a fuel injected small block would get similar mileage.

 

I would follow the same approach that GM is taking for their new Vehicles...
Small displacement, economical running, DOHC, V8 Engine with Variable Valve Timing and Turbocharging...
That will wake up the Engine, as soon as the Accelerator-Pedal hits the floor, to double the Horse-Power!

Welcome to the 4.2L (255 CID), VVT-DOHC, Twin-Turbocharged, V8, Cadillac Engine (Blackwing).

Also now in production, as a Non-Economical, Hi-Performance ONLY, Corvette Variant...
The 5.5L, VVT-DOHC, Twin-Turbocharged, V8 Cadillac Engine!

How about an all Aluminum 4.8L Gen-IV Engine with small Twin-Turbochargers:
-using an Aluminum 5.3L Block
-VVT
-Custom Camshaft intended for economy
-Aftermarket Connecting Rods and Pistons for high Boost pressure
-Water cooled Twin-Turbochargers at 30 to 40 Psi.

 

First time a Corvette has run a Cadillac (Designed) Engine!


O... if any of you are asking yourselves: why does the Cadillac Engineering Sub-Division still exist?
Well, they were the group that Designed the first ever produced "Fully Automatic Transmission" (using a Fluid-Coupling).

So they are still held in very high regard... and GM has not gotten rid of them yet!

 

One of the best additions one can have when determining best driving habits for maximizing MPG.
https://www.johnsavesenergy.com/vacuum-gauge

 

Well at least that article was mostly correct.