How to drive this hill - Fuel Economy, Hypermiling, EcoModding News and Forum

Eddie25 · 07-30-2015, 06:40 AM

i have this big 4km or 2.5 mile long hill to climb on my way home every day. its about a 1:16 grade and my underpowered fiesta struggles. i currently have 2 techniques.

First one is to floor it just before the hill building speed to about 110kph or 70mph. Then for the first 2 to 2.5km i have to keep my foot firmly down to avoid losing speed. The hill flattens out a bit at this point before becoming steeper again later on. but from now i can feather the throttle giving me just enough momentum to end the hill climb at about 75 kph or 46 mph.

The other technique is to start slow and feather the throttle at about 80 kph. However at about the last 1 to 1.5km of the hill the car completely runs out of steam and i have to gear down to 4th make it to the top. i dont have any measurements or instant readouts to help me determine which way is the best.

RedDevil · 07-30-2015, 07:53 AM

I'd start out in fourth gear to begin with, when you floor it you will go into open loop and the engine will be wasting fuel.
Chances are that in 4th gear it can make it at 80% throttle and have closed loop and no waste; that would compensate for the extra revs.
Not having to speed up also helps - less wind drag.

My UltraGauge has an open loop indicator, such a thing could be helpful.

Fat Charlie · 07-30-2015, 09:12 AM

+1.

That's what gears are for, letting the engine work at its best range.

MetroMPG · 07-30-2015, 11:23 AM

Time for an OBD fuel economy display!

You won't regret getting one - it makes the drive into even more of a game.

Eddie25 · 07-31-2015, 03:49 AM

this is true my car will make it up in 4th gear with less throttle. i do want to get a gauge but it is just so expensive getting one into this country. i would rather put that money into something like a set of echo tyres. i do have any obd2 im sure it can also tell me weather im in closed or open loop. i just need a ne android device my son destroyed mine. i still dont really understand what this 'loop' means but i ill be searching the forum now.

oldtamiyaphile · 07-31-2015, 08:54 AM

Open loop means your ECU is ignoring the O2 sensor and running rich, this happens on start up and at high engine loads as a protection measure.

trooper Tdiesel · 08-03-2015, 10:12 PM

4th or 3rd gear
so its at a point you can smash it WOT and gain speed not just keep going the same speed.

plus all the normal stuff, windows up, lights off; so-on ECT

30 mph = about 50 kph
40 mph = about 65 kph

i know that's way under 80 kph +
but it really helps limit aro drag..

dirtydave · 08-03-2015, 10:48 PM

video would help alot

PaleMelanesian · 08-04-2015, 04:20 PM

I'm a big fan of high load and low rpm so I lean towards the 5th gear approach. It depends on what you mean by "floor" it, though. If you're actually flooring it (max throttle), then 4th gear would be better because it's likely tuned to run rich on full throttle. If you're using heavy but not max throttle, 5th gear is good.

AbramWagner · 08-04-2015, 04:28 PM

Quote:

Originally Posted by PaleMelanesian

I'm a big fan of high load and low rpm so I lean towards the 5th gear approach. It depends on what you mean by "floor" it, though. If you're actually flooring it (max throttle), then 4th gear would be better because it's likely tuned to run rich on full throttle. If you're using heavy but not max throttle, 5th gear is good.

I agree

In my experience I can almost never get higher instant mpg readout in 4th as 5th at a heavier load. At the point where I literally can't maintain safe speed and have bled off too much momentum is when I switch to 4th gear

I also try to get a running start of higher speed before the hill to bleed off gradually

In my head I think 5th is the only choice but I could be wrong and also maybe be my individual car it works best