mark21742

We always talk about getting the most power out of a vehicle, but here let's openly talk about how to try and get the highest possible fuel economy with things like the best HP to weight ratios, turbos and other ideas.

Let's start with a 4 door geo metro body and bass everything off of it, keeping it front wheel drive and all 4 seats, but most everything else could go that wasn't needed as long as it stayed street legal and safe enough for tour family to ride in

S10xGN

iTrader: (11)

In reality, it takes less than 25 HP to motor a fairly new car at 60 MPH down a level road with no wind. That 25 HP will require "x" amount of air and "y" amount of fuel. Anything you can do to minimize the HP requirement to maintain that speed will result in better MPG. MFG's spend millions on wind tunnels, use synthetic oils, and high quality tires to help in their MPG quest. The bottom line is, minimizing the HP "requirement" to maintain your desired speed is what's important, not how the (or how much) HP is produced.

got-a-ls1

iTrader: (12)

mpg is for priuses or is it priuii? anyways FPG is where its at. fun per gallon... lol carry on.

meine96ws6

iTrader: (4)

This doesnt make sense, the cars offered today (focus & corrolla) are excellent choices for fuel economy.

AmishAssassin

iTrader: (2)

There is also a assumed amount of rolling resistance depending on tire size in that equation some where.

mark21742

The sad thing is some of the Honda civics were getting better mpg in the late 80's- early 90's than the new hybrids....in the 50+mpg range.

How about powerplant choices....gas n/a, turbo, diesel.......

I just started this thread to look at the normal **** box daily driver.....I'll take my gas gulping GTO over anything, but the less we spend on our daily commute and runs to the store the more money we have left to dump in our fun cars lol.


Just think how nice it would be to spend $10-$20 every week or two for gas again like we did ten years ago!

SS10Tech

Lean AFR mixtures upwards of 15.5:1 for EFI is a big one. Modern vehicles average 14.7:1 - read this fact somewhere but cannot remember.

Properly inflated tires. Wheel bearings in excellent shape. Tires properly balanced.

Intake valve events - closing 5* ABDC to get the most from every intake stroke. Building a motor for strictly making torque and keeping the RPM's way way down. High compression yields better fuel economy for more efficient fuel burning.

Not moving a 4,000lb vehicle around - lighter the better. Personally i removed the spare and jacks, took the tools out of my truck, and went to synthetic blend in my pickup truck when gas hit $4.11 a gallon for **** 87 quality.

Little things add up to make a big difference.

01 ss vert

iTrader: (1)

Gearing is key. If you have an engine that makes loads of low end torque at part throttle, you can have it run very low RPM with very little throttle input to keep it at constant speed.

Ever notice some cars do not get the fuel economy you would expect them to? A good example is the miata - it's small and has a small engine...why isn't it knocking down 40-45mpg? I think because if you geared it any lower (numerically), you would have to give it more gas to keep it moving - meaning load. Having an 8th gear, but running at 90% load defeats the purpose of saving gas if the throttle is mashed. WOT is WOT, doesn't matter the gear. The engine may be spinning less RPM, but the fuel being injected is much higher at the higher throttle inputs.

Matching gearing with torque, is key, IMO.

Weight being the next big factor to focus on.

Driving style being the 3rd biggest factor.

mark21742

One of the biggest things I never understood is these people that look down on us for driving our big v8's when (if you drive right) you can pull 25+ mpg out of an f-body or the like.

But seriously by now when it comes to the little **** box Eco cars we "should" be pushing closer or above 100 mpg by now with the technology we have....look st the smart car, if it wouldn't be shaped like a brick and have a lot lower roof line you could probably have a back seat and better mileage.

I always had the thought of taking some well known/established drivetrain like the good old Honda d16 or Vtec b16 and dropping it right down behind a low slung pair of seats in a small tube chassis (think Ariel Atom), but small light weight full aerodynamic body, nice light/low coilover front suspension and light strut setup in the rear and a nice high overdrive with a light narrow set of wheels to finish it off...

SS10Tech

Side fact - one of my buddies at work - his son is a Mechanic for a Honda dealership and also does inspections. More often than not those d series come in with zero oil in them - literally bone dry - yet they still run. he told me it happens weekly on the vehicles he gets in. That is not supposed to work but yet it does lol