Quote:
Originally Posted by SentraSE-R
Hypermiling technique will vary with your engine, transmission, and vehicle. Since your truck is an automatic transmission, I'd monitor instant mpg, trip mpg, load, instant G/H consumption, ignition timing, and rpm. You want to accelerate gently enough to keep your torque converter from slipping, so you watch the rpms to make sure they don't jump from 1800 rpm to 2200 rpm or (horrors) 2500 or 2800 rpm. Similarly, you watch your load to see when it triggers the transmission kickdown. If it happens at 45 load, you want to keep your acceleration below that level. Under that level, keeping your load higher allows you to get better brake specific fuel consumption. Manual transmission owners have major advantages here. They can accelerate for maximum BSFC with no torque converter to worry about.
Instant G/H allows you to see the difference in fuel consumption between coasting in gear and coasting in neutral (engine on, of course). It's logical to think you'll consume less gas at 750 rpm idling in neutral than at 1800 rpm in gear, but your truck may have deceleration fuel cutoff. IG/H lets you see the difference. It also helps you visualize how much fuel you're throwing away idling at a 3 or 4 minute stoplight. If you're using .35 gallons/hour, and do that for 1/15 of an hour at a 4 minute light, you'll waste .35 gal X .067 or .023 gal just idling at that stoplight. For a 10 mile drive where you might average 17 mpg, you'd use .588 gal. That 4 minutes of unnecessary idling adds .023 gal of fuel consumed, which increases your gas consumption to .611 gal, and drops your avg mpg down to 16.36 mpg compared to the same drive with the engine off at the stoplight. So you're going to learn quickly that you should shut off your engine at most stoplights.
It's up to you whether you'll try driving with load or pulse and glide. Many AT drivers find DWL (while trying to maximize ignition timing) the most effective hypermiling technique. I've had good success doing high speed P&G. I got 43.7 mpg out of a rental Kia Rio on a 3600 mile trip with 3 adults and all our luggage this Spring, P&Ging between 55 and 65 mph most of the way.
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Thanks for the helpful post!
I currently coast in neutral whenever possible (no decl. fuel cutoff). And while I hadn't heard of DWL (I had to look it up) I'm already doing that. Generally on flat highway cruising I stick with cruise control. I'll keep playing with it and watching my gauges and see where I end up.
I searched for months trying to find the truck I wanted with a manual. Rare as hen's teeth... So rare was that option that they eliminated them completely in new Chevy 1/2 ton trucks (I think Ford and Dodge too).
Mike