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-   -   Best way to get up to speed? (https://ecomodder.com/forum/showthread.php/best-way-get-up-speed-33770.html)

Striker2237 05-02-2016 09:52 PM

Best way to get up to speed?
 
How should I be accelerating in my powerful vehicle? Should I try to keep the RPMs below converter stall (1700ish) and just allow it to kind of glide up to the speed limit or should I be bringing it up to TQ peak or perhaps allowing some boost to get it to speed very quickly?

Mustang Dave 05-03-2016 09:42 PM

It depends on the particular vehicle. Is your "powerful vehicle" 2WD or 4WD? 4WD vehicles normally get less MPG than 2WD vehicles. Generally, keeping RPM 2500 or below while accelerating at high engine load is beneficial. Wasting too much time accelerating is detrimental to fuel economy.
Quote:

...allowing some boost to get it to speed very quickly?
??? Until you install your planned supercharger, there is no "boost" on that vehicle.
My experience with hypermiling automatics has been very limited until recently. I purchased my 2013 F-150 4X4 on Mar 29. It has the 5.0 liter "Coyote" motor and 6R80 6-speed auto. From my experience with my Mustang, I limit acceleration RPM to 2000-2500. (most of the time) :D I also limit my speed to the posted speed limit. My tires on both vehicles are at sidewall max. (50 PSI)
Your mileage may vary.

And don't consider EVERY stoplight to be a "Christmas tree". :D

UltArc 05-03-2016 10:26 PM

This is all MY observation, and not very scientific....sorry lol

In traffic, I can turn onto a road and basically 1st to 4k RPM, 2nd to 4k, and then 6th and I am cruising at 45-60 MPG (depending on vehicle and environment temperatures).

With no traffic, I go 80% engine load, and shift around 1750 RPM. Maybe 2k+ and skip shift.

If I don't have anywhere to be (and I've gotten the first method out of my system lol) I take 1st to 6 MPH, 2nd to 11 MPH, 3rd to 20 MPH, 4th to 25 MPH, 5th to 30 MPH, then 6th I keep at MPG of 30+ MPG. Slow, but the best way.

(Cough cough, Redneck) Lately, I have been able to accelerate at 40+ MPG on a flat [road] when going 35 MPH +.

So, I'm really no help at all. I'm not an auto, and I have no conclusive information, and my data is basically "don't do it too slowly, unless you go super slow."

But I hope you learned the REAL lesson. Every vehicle and situation is different, you'll have to experiment and monitor your vehicle to find what works best for you :)

Jack-Lee 05-04-2016 04:34 AM

Hi,
i accelerate between 2000-4000rpm with about 90% of the max torque. I "delete" the wide open throttle enrichment with a screw under the pedal.. Not optimal, but better then the enrichment with full opened throttle.

I starting with the first gear without a great acceleration, shift to the second, accelerate to 3500-4000rpm, shift to the 5. gear.

I drive a VW Polo 86C with 1.3l gasoline engine

mcrews 05-04-2016 10:11 AM

let apologize up front......;)

'best way to get up to speed?':confused:

"start at the top of the hill.....":thumbup::eek:

ok, I got that out of my system.....:rolleyes:

slowmover 05-05-2016 07:56 AM

Establish best habits. 80-90% of "absolute best" as a habit is worth than inconsistency.

Consistency. Drive fewer miles, overall, in the course of a year to accomplish the same ends (is more important).

Drive the fewer miles at a higher skill level. But do it on a consistent basis. What feels comfortable. But is proven better by your records to have positive impact on reducing your annual fuel bill.

If you don't know that number, it is where to start. How to accelerate is too small a detail to matter, at the beginning.

Mustang Dave 05-05-2016 10:33 PM

Quote:

Originally Posted by slowmover (Post 513444)
... How to accelerate is too small a detail to matter, at the beginning.

Excellent point! After years of adjusting my driving techniques for fuel economy, acceleration technique is insignificant in the grand scheme. In my (documented) experience (see my fuel log), having fun versus "putting a raw egg on the accelerator pedal" really doesn't make a significant difference in average fuel economy.

mcrews 05-06-2016 12:22 AM

Quote:

Originally Posted by slowmover (Post 513444)
Establish best habits. 80-90% of "absolute best" as a habit is worth than inconsistency.

Consistency. Drive fewer miles, overall, in the course of a year to accomplish the same ends (is more important).

Drive the fewer miles at a higher skill level. But do it on a consistent basis. What feels comfortable. But is proven better by your records to have positive impact on reducing your annual fuel bill.

If you don't know that number, it is where to start. How to accelerate is too small a detail to matter, at the beginning.

Well said!!!! and true.:thumbup::thumbup::thumbup:

JRMichler 05-06-2016 01:11 PM

Quote:

Originally Posted by slowmover (Post 513444)
How to accelerate is too small a detail to matter, at the beginning.

Very true. I did some comparative testing and found that "normal" vs "drive like a grandma" acceleration made almost no difference to gas mileage. So I accelerate at about 3/4 throttle, shift at 2500 RPM, and keep up with traffic.

slowmover 05-07-2016 08:44 AM

If I drive, on average, 12,000 miles/yr, then the cost (let's measure in gallons versus dollars) on an annual basis can be related to other costs more easily; that of depreciation, finance, insurance and the rest. These need to be expressed as a cost per mile. Cents per mile.

This is the big picture.

Sure, reducing fuel cost is advantageous. But most Americans do no more than factor monthly payment and weekly fuel cost. Have to break free of this

DHS released a study a few years back which revealed, generally, that 90% of us drive to 90% of the same places 90% of the time. Work, grocery store, library, post office, etc. So, this is where to begin. A better route to the office even if it is longer. No idling. Etc.

Same for errands. Combine them to one Saturday morning trip, as an example, and then use "Best Order Routing" to go to the farthest point first (by freeway, preferably) and work back to the house in a loop which features no left turns, etc. As does UPS or FedEx. Cut the miles and cut especially the number of cold starts. Eliminate the convenience store runs altogether.

Once on the better route -- to work or errand running -- find the legal speed which best fits never having to stop. This is the heavy vehicle penalty. The more one uses a route and familiarization kicks in, questions like how to accelerate fit themselves in.

One "wins" at the FE game, IMO, when one reduces cold starts, total miles to achieve exact same ends, and has reduced CPM annual cost. It's the percentage gain to the bottom line, annually, that matters.

My near 8000-lb pickup truck is different than yours. But I took the challenge from a fellow owner here that the discrepancy between highway and city numbers was a bit false. It is explained almost as much by my driving (the big picture above) as it is by non steady state operation.

I applied the above and saw a 22% increase over an 1100 mile period. Understand that I was already driving in manner appropriate to FE. Most would be very happy with the city number I had already achieved. Same for highway.

Comparisons to others need first be filtered by truck spec, climate and terrain. And only then to driver motivation. As you can see it's hard to do. Most never get this basis. And focus on a number which may have little to do with their particulars.

Start by keeping records. It's the only approach that works. On paper or online. Takes about 5000-miles to come up with a decent average, and only past four seasons can one be accurate. Questions like how to fill the gas tank or how to accelerate really don't matter.

Making sure -- verifying -- that mechanical systems are in ideal shape is the best first step, IMO. Book maintenance with service periods reduced by 10% is a suggested start. Get ahead on this. Alignment, brake drag, steering slop, etc need to be examined. Even brand new.

The use of the block heater year round is another. Especially for a work commuter. Same for a winter front, gas or diesel.

Tires and steering are the big ones on a pickup truck. Best choice of the former genuinely pays. No other mods really do. No free lunch, in other words.

I start by weighing the truck. CAT Scale. All four corners. The heaviest individual position determines the minimum per axle. Driver, max fuel plus usual tools and gear aboard. Then I work with tire pressures. I very strongly disagree with tire pressure bumped way up. Pickups don't need to be even more rollover prone than they already are. The minimum plus 5 is a decent place to start. (Probably, to stop). Inside the vehicle manufacturers door sticker range.

I also favor better shock absorbers (KONI first, Bilstein second). Poly antiroll bar bushings. I equipped my one ton with a rear bar where none was present, and had to upsize the front to maintain balance. (Fred Puhns book on handling a basic). Tires already last me over 100k as do brakes. Better handling means easier to handle curves and turns, but not at the expense of tire or brake life (as these are EQUALLY important as fuel mileage).

Greatest amount of work for highest miles at lowest cost with highest reliability, is pretty much my mantra. FE is but one measure.

Were I in your shoes I would start my record keeping by finding the average mph of the truck. Engine hours divided into total miles. Below 27 is unacceptable. Period. If one can get this number higher, then one is set on the right road. THIS is how I took my four ton truck to 23-mpg in the city for that 1100-mile period. All of the above had to come together to make it happen.

Good luck.

slowmover 05-07-2016 09:20 AM

Quote:

Originally Posted by JRMichler (Post 513567)
Very true. I did some comparative testing and found that "normal" vs "drive like a grandma" acceleration made almost no difference to gas mileage. So I accelerate at about 3/4 throttle, shift at 2500 RPM, and keep up with traffic.

The drivetrain sort of dictates. With my manual transmission diesel -- and using every gear every time -- I'm looking to set turbocharger pressure to a constant. That is, to have rolling momentum with each shift. "Progressive Shifting" a topic from the big truck world.

Mainly, one is cognizant of gear spacing. Slower at first (gears are close together) and faster as one progresses. Or, a higher rpm as one goes along. I don't ever wind it up except when towing. And then only in Fourth or in Direct. A man trans Cummins is ponderous in acceleration. There is no keeping up with the stupids. No point.

I'd rather have them go around me from stoplight to stoplight in any event. My concern is to not have to stop AND to preserve maximum distances from them. Same as when I am in the Kenworth.

Knowing when AND HOW to shift is the other. Especially something like a downshift on a downgrade with wet road and 35' trailer in tow into a 110-degree turn. That trailer WILL push the barely heavier truck sideways if I am too fast. What is applicable here is that NO drive is ever exactly the same. Even on a route driven hundreds of times.

It's a different world than with an automatic. Today's six and eight speed autos do an excellent job. For the most part I would want to learn how the computer does it. My impression is that vehicles are set up for prompt acceleration. I'd imagine it can be worked with going up or down. Solo or towing.

As a pickup is meant to do work I'd also learn to drive solo with the truck loaded to GVWR. There is no excuse to increase wear and tear in any substantial way when so doing. A big load of sand or gravel. And using the scale to understand FF/RR balance. A larger bag of acquired skill makes for better driving all around. One is slower, relatively, but faster in decision-making.

An empty car with one person achieving high numbers is just a stunt. Almost meaningless. Let's see how well FE is accomplished when loaded to max. The practical design of the vehicle.

I don't only heat or cool one room of the house. The challenge there is to find the appropriate balance. Same with a vehicle. Load it heavy and drive it for six weeks and FIND what is necessary for those wet downhill turns. No sliding, no panic braking. Get the learning curve behind one.

Some will say it is too hard on the vehicle. I doubt that as I've done it. Cars and trucks. One finds weak spots in operation -- driver and vehicle mechanicals -- pretty quickly.

For that day it may really matter. No money, no job and no home. Gotta go. Natural or man made disaster. Doesn't matter the reason. It's what I'd assume any father would want to know. How to get all the way down that long road with what little remains to us in cash and possessions. Safely.

To know ahead of time the likely fuel burn given traffic, torn up roads, bad weather, etc.

Sunny day solo driving isn't a guide. Anymore than is reducing the annual fuel bill. It's only with a maximum load on good tires and brakes -- having some practice -- that ensures best possible mpg under stressful circumstances.

So, accelerating with traffic? Yes, drivetrain dictated. But, both light AND heavy. In all weather. ETC.

Then and only then, IMO, is a pickup trucks practicality a given. Vehicle weak spots and driver weak spots exposed and repaired.

Range in 5-15/mph traffic is 3-5/mpg. Any vehicle. Biggest fuel tank wins. But why a pickup "could" be the practical choice when fuel availability is unknown (see any hurricane evacuation and extrapolate for other types). One must get 150-miles down the road, first. That's an average.

So, how to accelerate? Really, it's more on how to use the brakes. Acceleration and deceleration events. Practice while heavy informs all use.

In a man trans turbo diesel like mine, it's what gear. Not rpm or posted road speed limit. For a multi speed auto some of this will apply. Find what works. Minimal throttle movement and least use of brakes for a fully laden truck is the goal.

Acceleration takes care of itself, with this approach.


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