Are you lost? Because you sound like you are very lost.
MPG on your 3rd Gen?
- Thread starter clarkie470
- Start date
hiluxsurf1
New member
I believe the imperial gallon is different from the us gallon but we use litres here which is about 1/4 of a us gallon. Which I now realise makes my earlier post about fuel prices incorrect
brillo_76
Elite Member
In the 3rd gen forum. 1996 to 2002. So you may have better luck in the 4th gen forum..
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Rushthezeppelin
New member
Been mostly doing city driving since I got my 98 5 speed 5vz and I've been getting a very consistent 17mpg. Today I went on my first day snowboarding this season though and tracked that all on is own. 21.12mpg! That was with going over 4 passes, using 4hi twice for a few minutes, I'm guessing somewhere around 12k elevation gain and loss, driving slow in some areas that weren't well plowed and 270 miles. Was super happy with that number. One thing that maybe I'm totally off base with, does getting upper end of expected mpg on a vehicle generally indicate good engine health? I haven't gotten around to doing a compression test yet (got a tester though last week) but in my mind something like bad compression would lead to power being robbed and lower mpg.
jross20
New member
I still say there is some "secret" to the 5VZ-FE that I've yet to discover because I've never had a vehicle with such inconsistent fuel economy. With the same driving I can average 19 for several weeks and then suddenly average 17 for a few weeks, then sometimes 18.
Right now she is in the 17 range and, of course, I've no idea why. She seems to do better on non-ethanol but then she also does better with high octane in terms of pining on 87. High octane non-ethanol is extremely hard to find but gave me a good tank once.
If anyone ever had the cash/time to do such a test, I'd love to see someone do an experiment in which:
Right now she is in the 17 range and, of course, I've no idea why. She seems to do better on non-ethanol but then she also does better with high octane in terms of pining on 87. High octane non-ethanol is extremely hard to find but gave me a good tank once.
If anyone ever had the cash/time to do such a test, I'd love to see someone do an experiment in which:
- They confirm compression is good.
- They confirm the timing is correct/perfect.
- They confirm the alignment is good.
- They run a NEW catalytic conveter.
- They ensure all joints are fully greased.
- They ensure the MAF sensor and throttle body is clean. (Or is the throttle body thing a myth?)
octanejunkie
Elite Member
These vehicles were designed to run 87 octane, if you are pinging on 87 then you're either carrying an excessive amount of weight, putting a ton of load on the vehicle, or the ECU is messing up your ignition timing.
Nobody bought this vehicle for fuel economy, ever, so I don't think many people will spend the time to do the level of research and evaluation that you're talking about, but if you're getting between 17 and 18 miles a gallon on a 23-25-year-old vehicle, you're doing pretty good considering it was 15 - 19 from the factory.
sportscarfan
New member
With 85, 87, & 91 being the only widely available octane choices available here, I can confirm that running 85 in my 5VZ-FE (manual trans) will detonate/ping with load at low RPM. I tend to run 91 and get a pretty consistent 18-19. I do drive it fairly light footed though.
Rushthezeppelin
New member
Maybe someday soonish I can help out with that. I've got greased joints, just replaced CVs today too, rear axle will have all new bearings very soon (already did the seal job on one side and have the parts for the other). I will be running a compression test sooner or later here (got the kit already) and I'm hoping that comes out good (hopeful that it's at least going to be halfway decent with the way the truck runs right now). I'm pretty sure my cat is quite new (I assume probably got stolen during POs ownership as there's no rust on it). I'll have to check the MAF and just clean it for gits and shiggles. Should be getting alignment pretty soon when I replace my OTREs (will also be deleting the diff drop and replacing my rack bushings when I get around to that). The timing I'm not sure how to check yet though.
Also might want to include new O2 sensor in that list.
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Rushthezeppelin
New member
I've not seen knock with 85 (also up in high elevation with you) but I'm not carrying much of anything usually. Good to know that I need to up to 87 if I'm hauling any serious amount of stuff. Still a little lost how someone is reporting getting better milage with higher octane, that's not normally supposed to be a thing. Octane rating is supposed to purely be about what pressure the fuel detonates at.
phattyduck
Elite Member
I'd be surprised if a 5VZ gets better mileage on higher octane than 87, though 91 is needed if you are supercharged. The ECU ignores the knock sensor until ~3k RPM, so if more or less timing is needed below that point, it can't/won't adjust. (that lack of low RPM timing adjustment is exactly why the supercharged guys have to run 91/93)
On many other engines (though definitely not all!), higher octane gas can lead to higher MPG - if timing can be advanced due to the higher octane, the slower burn and earlier ignition can lead to more overall energy extracted from the fuel. My Mom's old '99 Solara V6 (1mz-fe) would get enough better fuel mileage on 91 compared to 89/87 that it was worth the extra cost...
-Charlie
You can observe the ignition timing with a scan tool that provides live data. they are widely available at auto parts stores. Even a relatively inexpensive model can provide the necessary data. Without a piggyback computer that is capable of intercepting and modifying the crank sensor signal, you cannot modify the timing on these engines.
jross20
New member
Oh yes good call on the 02 sensors.
Basically like a "best case scenario" or "closest to new" test.
What about the idle air control valve? I've heard people talk about cleaning and replacing it but I think that just affects the idle? I can't imagine that would affect economy while driving. Or would it?
Only only detail I can think of is being able to tell whether she's running rich or lean.
jross20
New member
Sorry I should have specified. I mean like make sure that all three timing gears are perfectly lined up when the timing belt is changed. It's probably uncommon but I have heard about guys who have discovered that one of the cams was off like one tooth.
jross20
New member
Well she only pings once we start going up hill. Now note that I do make a good practice of pressing the gas just enough to get her to ship so that way she's not trying to go uphill in forth gear, but still. But don't get me wrong, I would love to figure out if there is actually some kind of problem and fix it.
Back on gas mileage, my point is that this vehicle is the only one I've ever driven in which:
- Fuel economy is very inconsistent with the same driving week to week.
- I cannot get more milage than sticker. Any other vehicle I've ever owned I've always been able to get more than sticker with ease.
If you're not familiar, when I had a 2nd gen taco I once achieved 28 mpg on the highway and in general my average in town was 21-22 mpg. The thread is probably still up on tacoma would. Most guys told me that was unheard of. Lol.
It's more about wondering what the realistic true maximum is for 3rd gens with the 5VZ-FE. Back when these trucks were brand new I would be shocked if there weren't people out there that were able to average like 20-21 mpg with normal driving.
I mean unless somehow the epa sticker estimates were just literally absolutely flawlessly perfect. Lol
I've never gotten great mileage outta my 4Runner. It's been lifted most of its life and the rule I heard once was that for every inch of lift above stock, plan on losing 1 MPG on average. Factor in heavier, taller and wider tires than stock, plus the worse aerodynamics with them and the lift itself and it starts to make sense. These trucks are a big, square brick as well. I can get 20+ on the highway at reasonable speeds, i.e.; 62-65 MPH. That's about as fast as I can expect to go and get decent mileage. Above that and the MPG drops precipitously and you can watch the gas gauge move. I don't drive my truck gingerly around town, so I never get above 15 MPG.
I'm playing with some timing settings on my Piggyback to see if I can make a difference with MPG improvements and E10 gas, plus a new doo-dad I just installed that I'm not ready to post about. I'll update this as I drive the truck more on longer trips. We are going to the Oregon coast Saturday. We might be heading to Brown's Camp along the way to run a few trails as well.
I'm playing with some timing settings on my Piggyback to see if I can make a difference with MPG improvements and E10 gas, plus a new doo-dad I just installed that I'm not ready to post about. I'll update this as I drive the truck more on longer trips. We are going to the Oregon coast Saturday. We might be heading to Brown's Camp along the way to run a few trails as well.
What the mileage on the Tripmeter when the gas light comes on?
jgue467
Senior Member
Vornado?
2 of 'em.
Thanks. I figured as much. Regarding what you consider "around town", is this on city streets in traffic, with stoplights? And, do you run through a whole tank in those conditions? I live in a suburb. I can't imagine getting 18 mpg driving on the street in stoplight traffic conditions or running to the grocery store, etc.
EDIT: I know my speedometer/odometer is off by 6%, so I add the 6% to the Tripmeter "A", which is how I track my MPG per tank. I use Tripmeter "B" for Oil Life.
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jross20
New member
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