gas saving tips?

[thecheese429]

Hey, I know some people from New Braunfels!

As far as the bad FE, I have come to the conclusion that car makers make cars as inefficient as possible. The side effect is that they can then say that cars need more power, so they can make them more inefficient. (ok I'm done rumoring of conspiracy, but, it IS true )

If you're up for it, an engine swap would be one way to boost MPGs. If you put in a 4 cyl. power plant, you could tune it for either power or FE.

Short of that, putting light narrow tires on it, and airing them way up, would be a more realistic way of getting more MPG.

[Greeen]

A viper would be awesome with a 4 banger and skinny tires. DO IT! 16psi of boost is for losers 90psi in the tires is where its at.

[Gas Guzzler]

Originally Posted by Greeen

A viper would be awesome with a 4 banger and skinny tires. DO IT! 16psi of boost is for losers 90psi in the tires is where its at.

i just dunno if i could do that

[GasSavers_BEEF]

I think jay is running 80 psi...but he doesn't have a viper either.

[theholycow]

I run 80 in my truck's front tires and ~72 rear (manufacturer recommends 35, tire max is 80). My VW gets 51psi, the max stamped on the tire. It would probably be decent at 60psi but I get just a little bit of center wear at 51 anyway. Handles great, though.

[R.I.D.E.]

I had the fast cars many decades ago. Now I like to get great mileage. With the money you have in the high performance cars, you could part with one and get something like my Insight that has avaraged 65 MPG for the last 15 k miles. A manual would do even better.

Once you got the high mileage driving technique down pat the other cars could be a fun diversion and you could keep the miles down on them.

Sounds like you are burning about $50 a day in fuel. That's close to $20 K a year in gas and a lot of depreciation to say the least.

regards
gary

[trollbait]

If you're willing to go with a Fusion, don't forget to check out the hybrid. Good things are being said about it. The drawback is that it has less trunk space and no fold down seats compared to the standard model.

[shatto]

You drive a Viper for fun.
I once was next to a Viper in commute traffic. He was next to me then dropped back. Way back, leaving a big gap. Then he'd gun it and roar back up next to me. Never got out of first, but so what!

As to your commute;
I found that my Tundra gets damn good mileage at 2,000 RPM. About 63 MPH.
I set the cruise control and smile at all the folks who don't know the police are out there working hard to bring in money for government.
I theorize that the modern electronic cruise gives at least as good economy as me.

[theholycow]

Originally Posted by shatto

I theorize that the modern electronic cruise gives at least as good economy as me.

It's certainly going to give at least as good economy as you would if you were planning to hold a steady speed.

[GasSavers_RoadWarrior]

Smaller injectors...

Smaller injectors may offer a finer spray pattern, but will need to be "on" longer, you won't actually use much less fuel below 3 or 4000 rpm, after the first hour or so of running them, because the ECU will try to stay in stoich... Usually ECUs have a latitude of about 25% for adjustment, so if you go more than 25% smaller, you'll get codes because it can't retune the fuel trim that much...

Now, depending on the head, your intake ports, and your injection timing, 25% smaller injectors may be either be a benefit or a handicap... If your intake ports do not get very warm, typical of a crossflow head where they're not right next to the exhaust ports.. then what will happen is that when the duty cycle goes up to compensate for the slower flow rate, the injectors will not be spraying into an open intake valve as much... Usually things are set up so that at low RPM the injectors are actually finished spraying before the valve opens, but we're talking a small small quantity of fuel that has to evaporate off the port walls, it won't chill them much and the coolant can heat them enough.

If however, you get into a high injector duty cycle where ordinarily half the fuel would spray through an open valve but you cut injector size too much, you might double the duty cycle and get only a quarter flowing through the open valve, this leaves 3 times as much fuel in the port, and if you don't have very warm ports, it will chill them too much for it to evaporate fully. So you could end up with fuel puddling in the intake ports... You'll say to yourself, "But isn't this what happens at high RPM anyway when injectors are approaching the full allowed duty cycle?" ... Yes it is, but remember the engine will be making a hell of a lot more heat at that point...

However, there are ways to use smaller injectors to advantage, if you know your motor has larger injectors than other applications of the same motor, then going down to those may be perfectly okay. Check however the thermostat rating for that application, it might be 205 or 195 instead of 185. If you fit smaller injectors without a known application for them, then use a higher rated thermostat anyway, it will offset any problems with fuel vaporisation.

Another approach is to undersize the injectors and to turn up the fuel pressure at the same time, so the injectors are actually putting in the same amount of fuel but at a higher pressure. This should result in a finer spray and may even make the fuel "flash boil" as it is depressurised, meaning it turns instantly to a gas.

If the motor already has the smallest known injectors for that application, such as 14lb injectors in Windsor V8s, then tweaking the fuel pressure upwards, for up to 25% more flow should have the same effect. remember the ECU will shorten the duty cycle to keep 14.7:1 A/F ratio.

So anyway... 55lb injectors are a bit of a large drop from 72lb, but if you already have them, you can try installing them and tweaking the fuel pressure upwards a little, and also running a higher temperature thermostat.