I'm new.... Saturn and 4Runner w/ less than stellar economy!
 

I've been tracking my vehicle's fuel economy of fueleconomy.gov for almost 3 years now, surprisingly I always seem to have lower economy than the EPA rating AND the user community. I'm hoping to find ways to increase the economy, I'd like to see 32 MPG out of the Saturn and 20MPG out of my 4Runner. Below is a real chart of my fuel economy since 2004.

The vehicles:

1996 Saturn SL2 1.9l DOHC (Commuter):
https://www.fueleconomy.gov/mpg/cach...b76c7f3f07.png
https://www.fueleconomy.gov/mpg/cach...8f68486eb1.png

2000 Toyota 4Runner Limited 4WD (Recreation):
https://www.fueleconomy.gov/mpg/cach...1119cfb8f8.png
https://www.fueleconomy.gov/mpg/cach...6ce8e121b0.png

Welcome to the site rearviewmirror. Nice graphs. You seem to be pretty close to the EPA numbers for your vehicles. Off by one isn't that bad. A few driving techniques could get you over.

Welcome to GasSavers ! Yes indeed, those are nice graphs - Yes indeed, your goal mpg's are achievable (and then some?! ) .

You'll probably want to hit me with a wooden spoon but I'll ask anyway. Have you changed the ETCS?

Yep.. Changed all three (Trans/Air/Coolant) at ~100k miles. I'd like to see the Saturn hit 32, I can get 30 out of it on highway trips, but since it's a short distance commuter I imagine that's why I am just getting the minimum, plus I'm not very easy on the gas pedal. I wish it was a manual trans, I know I'd be able to achieve more in that case.

The graphs come straight from the fueleconomy.gov website, I've been tracking my fuel there for 3 years, I also track fuel prices in the comments section just to see how it changes over the years. I can also tell when something is going wrong with one of the cars because the economy starts suffering.

Welcome to GasSavers! As a Saturn owner I can say that your goals are definitely reachable. In fact, I'll go as far as to say that I think 40 is even possible. Can you tell us a bit more about where you are from so we can get an idea of the traffic/terrain you are dealing with? The first thing you can do, and probably the most cost effective(it's basically free:) ) is to increase your tire pressure to max sidewall. I would suggest maybe doing it a few psi every few days to get used to the stiffer ride. Again, welcome.

Thanks for the info... The Saturn shows a MAX of 44PSI, the 4Runner shows 65PSI MAX Cold. Currently I am running 35 PSI is both vehicles. With the ambient temperature pushing 95-100 in TX soon is it really OK to run closer to max pressure, I can see that generating some serious heat. My commute ranges from flat to mild hills.

Lastly, I can't imagine running 65PSI in the 4Runner, the manufacturer recommendation is 32PSI! I thought running them @ 40 might even be extreme, but now it sounds as if this might be OK.

Well you may be due for an upper o2 sensor. But I'd wait a bit before I changed it. The best thing you can do is work on your technique. Try to keep the car cruising in 4th gear with the convertor locked up. The more its locked the more improvement you'll see.

Rearviewmirror, I'd think 20mpg is doable for your 4 runner. I have a 2002 2wd 3.4L 4Runner and before using a scangague I was getting 23.xxmpg and with the scangauge I'm seeing 26.xx. Sure mines a bit lighter and has less moving parts but the EPA combined for mine is 18. I get 14.5mpg pulling a 3300lb boat on level ground so there just has to be room for improvement for you.

Things I have done:
-Mobile 1 synthetic in engine, transmission and differential.
-Michelin tires to 35psi
-Removed restrictive engine air intake snorkel since I don't go into deep mud and water.
-Disabled daytime running lights.
-NGK Iridium plugs
-Optima battery
-Removed the 3 rooftop runners of the roof rack. Still have the two elevated bits yet since its going to take a bit more effort to get them off. :)

Thinking of rigging an electric fan for the radiator but I'm not yet convinced its worth he trouble just yet.

rearviewmirror -

Welcome to GS! Since you have a 96 Saturn, it is not likely, but possible, that you have the "plastic" coolant sensor. The plastic one cracks. If it was replaced at 100K, then I am positive that it would have been upgraded to the brass version of the sensor. Did you do the replacement?

Anyway, *if* it was plastic, I think it would still be good at 110K+ miles.

I went and looked at the transmission specs for the 1997 Saturn :

https://www.gassavers.org/showthread.php?t=3122
(OK, I just saw that you posted on this thread ...)

The SL2 DOHC Automatic has a final 4th gear ratio of 0.700, which is closer to a "performance" gear. The SOHC automatic transmission has an "economy" 4th gear ratio of 0.595. I have the same problem with my DOHC "performance" final gear, but I have a stickshift and a much larger commute, so I can squeeze more out of it.

CarloSW2

CFG83, he has already changed it. Now you get to be hit with a wooden spoon! See my first post in this thread. :D

lovemysan -

I'm used to that, but it's usually one of the cats hitting me with the wooden spoon when he/she want's to be fed.

Yeah, the ECTS has been changed, but is it a *brass* ECTS (needed in the long run)? I am thinking it just HAS to be the brass one, right?!?!?!?

CarloSW2

Yep.. I replaced all three with the brass variety, I got them from the Saturn dealership directly after having learned the importance in the car's operation.

Tire Size question:

The Saturn calls for a 185/65-15, my car has 195/60-15 on it currently. Could this wider although stiffer tire cause the fuel economy to drop by 1-2 MPG? I'm just curious, if this is the case I might consider switching to some thinner LRR tires sooner than later.. Of course being hasty would incur a cost that would take a long time to recoup in saving a few MPG's.

rearviewmirror -

You can see the effect here :

https://www.miata.net/garage/tirecalc.html
Attachment 634

From what I can tell, when your tires were new, they were probably making it appear like you were getting more MPG than you were. Why? Because the odometer would be recording more miles over time than with the stock tires.

But the above is not proof because the odometer can be off too.

Assuming you are using your odometer to figure out your MPG, you should use a GPS to get the real scoop on your MPG :

New shoes (aka tires)
https://www.gassavers.org/showthread....ighlight=shoes

Based on my calculations, I am getting a 2% bonus over my odometer. That doesn't come out to 1-2 MPG, though. It is more in the range of 1/2 to 3/4 MPG.

NOTE : You're right about the cost. Since I drive freeways that have rain grooves (imagine the road lining up with the tread on my tire), I really feel the car "wiggle" at freeway speeds. Sometimes I feel like a phonograph needle. If only my tires had good songs on them ;) !!! Because of that, I have not taken advantage of my 51 PSI rated tires. I will probably test them at 50 PSI for fun one day, but not for a living. Except for that, :( , they're very good tires.

CarloSW2

hey that's a great link, thanks! I second the recommendation to test MPH with a GPS. Also tirerack lists real sizes for most of their tires, as they are often larger or smaller than the rated size indicates by a decent amount. In my case I found that my speedo/odometer read high by a few % to start with, and then my new tires were almost an inch bigger than there rating suggested, so the net effect was that my speedo was off by a rather different amount than I suspected.