better wiring better mpgs?

[mazdamx640]

So I'm trying to get better mileage out of my 96 lesabre and I'm thinking about upgrading some of the wiring to up the mpgs. I've already installed 2 gauge wiring from the alternator to the battery, engine block to the negative of the battery and the negative to chassis and it seems to have helped and now I want to rewire to fuel pump to up the pressure and help the fuel atomize the fuel better. zzp says that the stock 18 gauge wiring looses 1.5-2 volts by the time it reaches the pump. The car is wired for subs and I would like to add a distribution block off that and use the stock wiring to activate a relay think it will help? Also zzp sells a alternator voltage booster that ups it by 1.2 volts that I think might help too Easy Performance - Alternator Voltage Booster #EP-AVB-GM

[mazdamx640]

also found this but its hard to believe a alternator could make such a difference
High Output alternator (HO alt) = better MPG - LS1TECH

[some_other_dave]

Originally Posted by mazdamx640

... I want to rewire to fuel pump to up the pressure and help the fuel atomize the fuel better.

The pressure can be raised by simply changing out (or adjusting if it is adjustable) the fuel pressure regulator on the fuel rail.

You don't want to do that--higher pressure means that more fuel goes into the engine per millisecond of injector opening. So unless you have a way to re-map the injection times for all driving conditions, you will simply be making the mixture richer, and burning more fuel.

I think you've probably done just about all that can be done to help your MPG with bigger wiring.

-soD

[RobertISaar]

if you're dropping fuel pressure at normal voltages, you already have issues, either a weak pump or wiring.

higher pressure WILL cause a slight increase in fuel flow per time unit that they're opened, but well within O2 sensor correction range.

the HO alt getting better fuel economy..... maybe. his old alt could have been quite lossy and putting in a new one could have free'd up a little bit of drag on the engine. the alt could also be operating in a more efficient range. hard to say.

as for the "volt booster"...... if you like running on the ragged edge of frying electronics, especially your battery, by all means, go ahead. the alt's regulator is already targeting ~14.4 volts, pushing that into the 15 or 15+ range is a good way to turn what could have lasted 5-10 years into a yearly replacement item.

the way it works, BTW, is that it drops externally sensed voltage by x amount to trick the regulator into running a higher duty cycle to maintain "14.4". this will show up as more drag on the engine.

[Thenorm]

changing wiring for mpgs seems like the opposite of low hanging fruit.

i assume this must mean that your car is in perfect mechanical condition, with good LRR tires, you're an expert and pulse and glide and you have all sort of aero improvements and weight reduction?

[niky]

For a new car, it's usually a fruitless task, but considering it's a 96, there might be something found there.

Personally, I'd sand down and clean all the contacts first, on both the wiring and the grounding wires/straps and see if that makes a difference. Might be cheaper than going through the car and changing out absolutely everything. But if you find cracked or brittle rubber, might as well change that out.