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-   -   Who here drives a non-hybrid automatic and normally gets 50+ mpg (https://ecomodder.com/forum/showthread.php/who-here-drives-non-hybrid-automatic-normally-gets-14025.html)

sl2eggplant 07-28-2010 09:52 PM

Who here drives a non-hybrid automatic and normally gets 50+ mpg
 
In the "Garage", I notice a disproportionate number of cars with manual transmissions. I have an automatic and wanted to get an idea of how many folks here routinely can get 50+ mpg in their non-hybrid with an automatic.

I'm curious to see which cars (year, make, and model) have passed the 50+ mpg milestone. I'm lazy and its difficult to search since the mpg number may get skewed from some sub-optimal driving conditions. I'm more interested in what you can get on a good drive since we all may not get the chance to drive good routes.

Thanks in advance.

RobertSmalls 07-28-2010 11:40 PM

Nobody here does, according to the fuel logs:
EcoModder Fleet list - EcoModder.com

But we have a handful of people above 40lmpg with automatics:
EcoModder Fleet list - EcoModder.com

I think that's partly because you can hypermile a manual better to get a larger % over EPA. It's also because the kind of people who feel the need to get >50mpg are attracted to stick shifts and hybrids.

50mpg is a tall order for a four-speed torque-converter automatic, especially if you can't EOC or P&G. You could do it with a boat-tailed SL2, or with a car like the upcoming Fiesta: direct injection, tiny displacement, automated manual transmission. Or a 10 year old hybrid.

nayeliesuncle 07-29-2010 02:49 AM

I did manage to get 51MPG with my car.

Too bad the auto transmission broke.

comptiger5000 07-29-2010 09:15 AM

The lack of EOC is what's killer. I wish I had a synchro-ed transfer case, as then I could EOC by sliding the t-case into neutral and killing the engine. Right now, the only easy way to re-engage it is either stopped, or rolling approx 20mph with the engine idling in D (shifted to 3rd gear). Thus, I don't EOC, except for occasionally across a long parking lot.

Daox 07-29-2010 09:22 AM

I don't think its the lack of EOC as much as the inability to run the engine in the most efficient manner (high load, low rpm). I can still get great mileage using P&G and coasting with the engine on.

dcb 07-29-2010 09:38 AM

The benefits of EOC are more pronounced at slower speeds (as are the benefits of P&G) generally.

i.e:
if you burn .4gph at idle, and are coasting at 5mph, you are getting 12.5 mpg.
if you burn .4gph at idle, and are coasting at 20mph, you are getting 50 mpg.

MadisonMPG 07-29-2010 09:53 AM

There's a reason the number is disproportionate . :p

What happens when raise the throttle to around 85% in an auto? Thought so.

sl2eggplant 07-29-2010 10:10 AM

I should not count my eggs before the hatch, but Eggy (99 Saturn SL2 automatic) is doing very well.

I'll have to post the results in the "Success Stories" tonight once I confirm the numbers on my drive home. I have a 200 mile round trip daily commute which helps me to "unscientifically" test each aero mod that I now implement. Currently, I reinstated the HAI and results appear promising based on the scangauge estimates.

comptiger5000 07-29-2010 11:34 AM

When I eventually do some computer tuning on the Jeep, I plan to make it use TC lockup much more aggressively, as well as tweaking the downshift points. I should be able to get it to break 14 mpg around town no problem then.

Of course, being able to go to 85% throttle at low rpm isn't possible in this thing anyway, as it's got too much low end torque, so it picks up FAST. Unless you're turning less than 1100 - 1200, it's got plenty of pull even at 40% throttle (I can pass people uphill on the highway EASILY in OD with the TC locked, even if I'm going slow and only turning 1400 when I start picking up).

Trying to pick up at more than 50% around town wouldn't be sustainable, unless there were no cars in front of you. Plus, between the noise and the acceleration, it would attract plenty of attention from cops.

Nevyn 07-29-2010 12:16 PM

I haven't gotten my LMPG to 40 yet, but I'm close. No EOC for me, and I thought I didn't have DFCO either for the longest time! This will only be my second normal tank since finding out I *do* have DFCO.

RobertSmalls 07-29-2010 12:28 PM

Comptiger, it sounds like you have way too much displacement. A four cylinder would be more properly loaded during cruising, and you can rev it to 6000+ RPM on the rare occasion that you need lots of power. Though you may lose the ability to pass while going uphill. :-P

Tygen1 07-29-2010 01:09 PM

I'm doing pretty well in the old ZX2. I've had a few tanks over 50mpg but only in highway driving. For me, it's easy to get over 50mpg on pure highway trips. My commute involves too much city driving, or else I would be getting 50mpg tanks commuting. Otherwise I have been pushing every closer to 50mpg on my commute with some recent mods. I believe if I can get the latest mods to work consistantly, then I can achieve 50mpg consistantly.

BTW, no EOC for me, just a nice low idle gph of 0.20, but it can range down to 0.08 :D This helps a lottt!

dcb 07-29-2010 01:21 PM

Quote:

Originally Posted by RobertSmalls (Post 186048)
Comptiger, it sounds like you have way too much displacement.

and aero drag, and weight, and rolling resistance, and transmission losses... ;)

comptiger5000 07-29-2010 01:35 PM

Yeah, this thing has a bit more engine than it needs. And, it probably burns about 1gph at idle :eek:. Then again, the 4.0 I6 isn't much better for mpg either.

The 6.8 second 0-60 is great for merging onto the highway though, when you get stuck behind the idiot doing 25 up the on-ramp and not accelerating to merge into 60 mph traffic (happens a lot around here). Just punch it, merge and settle into a nice, slow cruise in the right lane. Plus, getting on from the stop sign ramps on the Merritt (or other short ramps), it's priceless to see the face on the guy in the BMW behind you when you punch it to get on in heavy traffic and tear away in a blast of V8 noise leaving him thinking "wasn't that a Jeep?"

Plus, the 5.9 Limited is a fairly rare special edition, of which only 14,286 were sold in America (not sure if the total includes US and Canada or just US). With the bigger engine and extra power came a slightly nicer interior, slightly different exterior, electric cooling fan, heat extractor vents in the hood, better exhaust system (most people don't believe it's stock when they hear it), the need for premium gas, and only very slightly worse gas mileage than the standard V8.

I'll agree with it having lots of aero drag. It's not terrible weight-wise compared to a lot of SUVs, it weighs about 4200 pounds. Certainly not light, however. Rolling resistance is actually pretty low. Especially if I neutral coast, but even in gear if not in DFCO, I usually gain more speed than most other vehicles down hills, even doing 60 or so on the highway with all the aero drag.

I plan to try to clean up the underbody airflow a bit, and maybe eventually do a removable kammback for long trips. More aggressive use of TC lockup should help out a good bit with the transmission inefficiency.

I can also help the engine efficiency a bit with small things like upgraded fuel injectors with a better spray pattern than the crappy stock ones, giving a better burn. All told, I hope to get it up to 15mpg around town and 25 on the highway (maybe with slightly taller gears).

Fortunately, once I leave for college in a month, it will no longer be subjected to the daily commute in city traffic, etc. and I should be getting much better mpg. My normal around town grind is terrible for mpg. Plus, once I replace the plenum gasket this weekend, I should get a little better mpg. Maybe I'll get to about 13 around town. I just try to stay positive and compare my mpg to the EPA ratings (11/16). I would actually have to try, especially on the highway, to get mileage that bad (I can break 19 averaging 65mph with the A/C blasted). I expect to get about 20 - 22 on my trip to college (350 miles). As long as I get at least 20, I'll be happy, as I'll be able to do it on 1 tank of gas without sucking it dry (23 gallon tank).

After college I plan to buy something more efficient and retire this thing from DD duty. However, for now, I need the cargo capacity, possibly the towing capacity, and the deep snow capability. And on the highway, all the low end torque makes it very pleasant to drive. It's not screaming along (turns about 1800 at 60mph). Plus, once it's in OD with the TC locked, unless I have to drop below 40 (or about 45 on the steepest of hills), it never downshifts.

sl2eggplant 07-29-2010 03:49 PM

Tygen1, I was surprised at your Escorts performance when I checked the fuel log a couple of weeks back. Most of the Escorts maxed out at 40 mpg and you had an automatic easily running 45mpg (90 day ave).

How did you get such a low consumptions for GPH. My car (1.9L) is about 0.37 in Drive idling, and 0.30 in Neutral.

C3H8 07-29-2010 05:14 PM

i have an automated manual, or is that manualised auto? anyways i can average low 40's over a tank if i drive carefully. i dont let me vaccum gauge go below 10 inches of mercury. no a/c, alternator disabled, power steering belt removed. i just dont think eoc has much benefit. that and i can control the torque converter lockup so i could, in theory, engine off coast. but i just dont think it's worth much mpg overall since i live in south florida and it's flat as kansas here.

the 2 main things that helped me was removing the cat, and removing the egr. maybe the cat was clogged, i dont know but it definitly helpd. the egr helped because not having it means the throttle plate is not as far open as it normally would if the egr was working. because the throttle is closed more, the computer gived the engine more ignition timing. for my engine, timing=efficency.

i actually did a-b-a testing by driving around with my scanner hooked up so i can see the ignition timing. pulling the wire on the egr valve cause it to jump up.

tumnasgt 07-29-2010 05:38 PM

C3H8, it's a manumatic, which is just a normal auto with the ability to shift as you wish. Makes your 40MPG more impressive :)


(my first post was going to be an introduction, but I really ought to be studying for university, so I'll get round to that when I have more time)

Tygen1 07-29-2010 08:59 PM

Quote:

Originally Posted by sl2eggplant (Post 186076)
Tygen1, I was surprised at your Escorts performance when I checked the fuel log a couple of weeks back. Most of the Escorts maxed out at 40 mpg and you had an automatic easily running 45mpg (90 day ave).

How did you get such a low consumptions for GPH. My car (1.9L) is about 0.37 in Drive idling, and 0.30 in Neutral.

Well I spoke too soon, I had a hunch when I filled up today that it was going to be good. 50.15mpg on this normal week of commuting. If I can get the latest mod to not make the PCM go crazy, then I could start to see consistant 50mpg tanks commuting.

I attribute the low idle gph to the HAI. It is in the high twenty's without it and the high teens to low twenties with it. It's real inconsistant though, real touchy. If I let it go to DFC, then kick it into neautral, then it will give the mid teens pretty consistantly, around 0.14-0.17. If I DFC, in gear, and let it run down to real low speeds, that's when I see the crazy low gph numbers. I have pictures to prove it!
In drive I see the same gph as out of gear, maybe 0.01 difference.
I've run some charts using an Idle GPH of 0.21 and looking at the percentage of Coasting I am able to do per day and I could only see a 3% improvement by EOC for my commute...maybe 1 mpg is not that big of deal. I do hope to do a MTX conversion next year.
I've been at this for a little more than a year, I believe anyone can do this with enough research and effort. It's not excedingly difficult be requires extreme patience and persistance.

sl2eggplant 07-29-2010 09:47 PM

Fudge.

Tygen1, glad to see the HAI is working for you.

I just permanently retired the HAI since it did not help my mpg and probably decreased it. I'm disappointed but happy to be rid of it so I can move on to something better. I got 46 mpg on this tank give or take some error from pumping at a different gas station ... expected 52 based on scanguage .... but I knew that I was running less efficient after burning my first quarter tank of gas since I was 20 miles below my mark for a 3/4 tank.

Well, hopefully I can break 50 mpg using the stock intake system.

Tygen1 07-29-2010 10:10 PM

I wouldn't give up on the HAI so quick, pump errors can really throw things off, just look at my fuel log of SG vs. Pump and will see some wild variations. Use your SG to track your IGN timing or LOD to give you an idea of how these changes effect things. If you PCM is pulling timing with the hot air, then it will hurt mpg. My PCM doesn't care how hot it gets, I just loose power and gain mpg. Either way you are doing great. It took me quite a while to sort things out, there are a multitude of factors that effect mpg.

sl2eggplant 07-30-2010 08:58 AM

I'll give the HAI another try probably in two weeks but I need to stabilize my mpg on my current setup and get a baseline for engine timing and load on the scangauge. I am expecting 48 +/- 1 mpg with the stock intake and no other changes to the car at the moment.


I've had the HAI in the car for at least 2 months in different configurations with temps from 100 - 240 depending on traffic. I definitely think most or all of the gains that I thought were from the HAI were actually from improved hypermiling. My thought is while I may be using less gas with the HAI, I have less power (obvious) so I need more throttle to maintain my speed (60 mph). Another thought is my car's pcm is just plain stupid.

About the gas pump error. The pump only had one little clicker thing to set at while most pumps I seen have 3 clicker things to set your gas flow. The gas was flowing in much faster than normal so it stopped at 8.2 gallons (~48.7 mpg). At that time, I knew that I was going to do much worse than expected and continued to pump once more and it stopped at 8.7 (~46 mpg) gallons. While the pump error is there, I'm pretty sure I topped off to what I normally do at my other gas station or pumped less than normal due to the high pump flow. Either way, I definitely burned more gas this round with the HAI and the scangauge erroneously inflated my mpg.

Phantom 07-30-2010 12:59 PM

Sl2eggplant how do/did you have the HAI ran? Did you just have the air filter open to the engine with no shielding or did you pipe hot air in?

If your engine cuts spark timing when it sees higher IAT (Intake Air Temp) you could try moving the sensor closer to the filter, that will help it see accurate temps since the sensor does not get heat soaked as much thinking the temp is higher.

Tygen1 07-30-2010 01:17 PM

Opps, I forgot one thing...let me elaborate.

Less power means a higher TPS which the PCM thinks means a higher load which normally means pulled timing. Typically our PCM's are designed to not have as much ignition advance as they could run. Short of buying nice software to reporogram the PCM, I ended up fooling the PCM into thinking it was at a lower load, even if the TPS was high. You may have read some threads I had about the vacuum leak giving me better mpg. Once I got the wideband I found that I was not lean like I thought, it was simply just more ignition timing. The vacuum leak made the PCM not believe the MAF and therefore it determined I must be at a lower load and that advanced the timing to near max. When this was coupled with the HAI, that's when I started to see the nice low GPH's and tremendously improved highway mpg. The ZX2 is starved for timing. With the lean burn set up I am using now, I am just bleeding off voltage from the MAF, which no doubt makes the PCM believe there is a light load. So I see max advance when bleeding off voltage from the MAF.

This may help you, but I don't know how your Saturn will react?

C3H8 07-30-2010 02:10 PM

another way of increasing ignition timing is by installing a 5K or 10K ohm potentiometer on the throttle position sensor. solder 1 of the 2 wires on the pot to the throttle position sensor's output wire, and the other wire to a ground.

then you have to use a scangauge or obd2 monitor to watch ign timing as you slowly increase the pot's resistance. this fools the computer into thinking the throttle is closed more then it really is, so it advances timing. on an automatic trans, this has the added benefit of lowering the rpm's at which the trans shifts, for more economy. my car has a manumatic trans, and when i have it in auto mode with the pot connected, it shifts into second egar at 10mph, 3rd at 20, 4th at 35 and locks up the torque conveeter at 40. in manual mode there is no differenced with or without the pot, except for the increased ignition timing.

another benefit of a pot on the tps, is that the torque converter stays locked up more often, even if you open the throttle a good bit. it still unlocks as it should when you punch it, or go over 50% throttle though. but for an ecomodder like myself, its virtually always locked up when driving at +40mph.

the last benefit i can think of, is that when decelerating from high speed, the computer cuts fuel more quickly, and cuts it for a longer amount of time because it thinks the throttle is closed more often. think of it as an automatic injector kill switch.

you can install the pot on the dash or centre console if you want. then s an option a on-off switch to one of the pot's wires so that you can disable the pot and return the car back to normal mode. also, once you have the pot dialed in, you can simply remove it and install a resistor in its place which has an identical value of resistance. a on-off switch also works with the resistor.
this frees up the pot to be used on another sensor, such as the map, iat, or maf, etc.

fooling around with a pot anbd the iat has a similar effect of advancing the ignition timing when you fake the computer into thinking the air is colder then it really is. it has a negative effect of watcing to add more fuel when you make the iat read cold, but the throttle position sensor that i previously lowered its value counteracts this. also the o2 sensor will not let the computer add more fuel soi the intake air temp sensor is also a good mod to do.

i have tried adding a pot to the map sensor, and this also effects timing and fuel but the computer quickly (in a matter of 2-4 seconds) relearns and works around the fueling change with the map sensor. this also has the effect of undoing any changes to the ignition timing that was made by changing the value of the map sensor. so for me at least, map sensor is not worthwhile mod.

what i have doscovered is that you can not perminantly alter any fueling tables by changing the value of any engine sensor. (with the exception of open loop mode such as a cold start). you can only change the ignition timing and transmission shift points.

sl2eggplant 07-30-2010 07:16 PM

Quote:

Originally Posted by Phantom (Post 186198)
Sl2eggplant how do/did you have the HAI ran? Did you just have the air filter open to the engine with no shielding or did you pipe hot air in?

If your engine cuts spark timing when it sees higher IAT (Intake Air Temp) you could try moving the sensor closer to the filter, that will help it see accurate temps since the sensor does not get heat soaked as much thinking the temp is higher.


I used a 3in flexible dryer hose and routed it to my air box. The three main configurations are

(1) Point the dryer hose right above the exhaust manifold (no shield)
(2) Same as (1) but added large aluminum foil pan shield
(3) Point the dryer hose away from the exhaust manifold

Keep in mind, I have a full wooden belly pan so minimum temps are around 100 - 110 F. The IAT has always been placed inside the air box probably a couple of inches below / outside of the air filter. Stock IAT location is in the plastic hose/funnel 2 or 3 inches outside of the air box.

sl2eggplant 07-30-2010 07:24 PM

Quote:

Originally Posted by Tygen1 (Post 186200)
Opps, I forgot one thing...let me elaborate.

Less power means a higher TPS which the PCM thinks means a higher load which normally means pulled timing. Typically our PCM's are designed to not have as much ignition advance as they could run. Short of buying nice software to reporogram the PCM, I ended up fooling the PCM into thinking it was at a lower load, even if the TPS was high. You may have read some threads I had about the vacuum leak giving me better mpg. Once I got the wideband I found that I was not lean like I thought, it was simply just more ignition timing. The vacuum leak made the PCM not believe the MAF and therefore it determined I must be at a lower load and that advanced the timing to near max. When this was coupled with the HAI, that's when I started to see the nice low GPH's and tremendously improved highway mpg. The ZX2 is starved for timing. With the lean burn set up I am using now, I am just bleeding off voltage from the MAF, which no doubt makes the PCM believe there is a light load. So I see max advance when bleeding off voltage from the MAF.

This may help you, but I don't know how your Saturn will react?


Thanks Tygen1. Saturns don't have an MAF, only an MAP and obviously IAT. I'll have to research how other Saturn owners are able to make the mpg gains.

I drove the car to the doctors today and when the engine was warm and idling, the GPH was around 0.35 which is lower than what I had with the HAI at 0.37.

sl2eggplant 07-30-2010 07:36 PM

C3H8, thanks for the tip. Personally, I've been trying to stay away from the more exotic electrical mods because I simply don't understand how they work. I'm more focused on the simpler mechanical mods that work all the time i.e. weight reduction and aerodynamics. I know that I will eventually start tuning the engine as I exhaust the aero mods.


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