Soon I'll be making my trek across the country, perhaps towing some light cargo with me. Right now I have my timing set pretty high, around 8 degrees, which isn't anywhere close to stock for a 305 TBI. This means I'm always putting premium into my car, because even though my engine's stock, I believe every little bit helps. heh. With that said...

Driving from North Carolina to Washington State is obviously quite a drive, and it's definately going to require a good amount of refuelings. I was thinking, it might be more economical for me to set the timing back down to 0* and use the regular gas. But then I got to thinking, with the extra weight, any benefits of using cheaper gas might be pointless if the loss of power when I needed it (when towing) would cause me to lose gas mileage. SO, basically... Here's what I want to know.

Would it be better for me to stay running premium and pay the extra money to fill it up so I can keep the power to tow, or..

Would it be better for me to set the timing down to 0 so I can run the cheaper fuel?

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else

 

Enkil,

Set the base timing closer to spec, but don't go to TDC. Maybe 4-6° BTC would be a good start. Leave NC on regular or mid-grade. Your fuel economy will be better, especially if the EGR is functioning correctly (you'll find out as soon as you start cruising). When you approach the western fringes of Nebraska or South Dakota (depending on your route selection) change to premium for the elevations. You'll likely be running just a little rich due to the thin air, even with the MAF correcting by measuring actual air mass (your BLM tables are learned in lower altitudes and will take a while to re-write on the trip). You will tend to run hot in the hill climbs and thin air, both because of lower air density for combustion charges and less heat rejection by the radiator, so detonation can be more of an issue.

Once you start coming down the mountains make sure the brakes are good, and the fuel can go back to regular or mid-grade.

BTW - I-90 and I-94 west of Ohio are pretty clear of any major construction projects right now, and watch out for handheld lasers in Indiana and Illinois.

You're not in Kansas any more...

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Later,
Vader
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"Let the bodies hit the floor!"
Adobe Acrobat Reader

 

Yeah, my EGR's brand new.. it better be working

I might not tow anything.. The only things I NEED to take with me are my clothes, and I can fit all those in the back seat of my car. The rest I can mail to myself later.

I might invest in an extra set of brake pads for the trip down the mountains though, since I have to go through two sets of'em. That, or I can find the terminal velocity of my car.

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89 iroc-z 305 tbi
k&n filtercharger, open element air filter. nuffin' else