Bad Gas Mileage.??? Getting Worse

Smallwood0507 · 10-22-2009, 01:28 PM

Alright so when i bought my 4runner last year it got 16 mpg and after 1 year and new tires (bfg's) it now gets 12!!!! Whats up with that i knew the bfgs would take off a little mpgs but 4 that cant be right....Any guesses to what would be going on???

This ad is not displayed to registered members.
Register your free account today and become a member on Yotatech!

BigBallsMcFalls · 10-22-2009, 01:42 PM

bfg can drop mileage
how you drive has a lot to do with it

get a scangauge II and figure it out

vital22re · 10-22-2009, 01:42 PM

check the tune up, maybe replace the primary o2 sensor, clean the maf. how fast you driving on the freeway? keep the rpm's under 3000

Ironmike4x4 · 10-23-2009, 06:36 PM

First off, how much bigger in size of tires did you go to? You will have to remember 2 things. Bigger tires= more weight and more drag; therefore, more load on the engine. Also you will have to realize the mileage will be off due to the change in tire sizes so there will be a difference.
Secondly you may be in need of a tune up as Vital said. If you can get a technician with a scan tool that can read O2 sensor parameters then they can tell you if it's reading properly. If you have a dead or lazy O2 sensor then it will affect the air/fuel ratio causing poor mileage and will not always turn on a CEL.
Finally, your cats may be on it's way out. The same technician can read this on the O2 sensor parameters by checking the post catalyst data.

96743runner · 10-24-2009, 02:12 AM

x2

But like others said earlier, it is probably the tires and your driving style that may be giving you that gas mileage.

nuke1105 · 10-24-2009, 07:20 AM

how many should i expect from my cats? I had a 4 cylinder taco and only got 80K miles out of them because they were pluged up due to lack of maintenance (my first car at 16 didnt know much). But now i have a 6 cylinder and im real anal about the service of this truck but since i bought it used how can i tell if i still have the originals and how many miles should i expect from them?

Smallwood0507 · 10-24-2009, 02:32 PM

Quote:

Originally Posted by Ironmike4x4

First off, how much bigger in size of tires did you go to? You will have to remember 2 things. Bigger tires= more weight and more drag; therefore, more load on the engine. Also you will have to realize the mileage will be off due to the change in tire sizes so there will be a difference.
Secondly you may be in need of a tune up as Vital said. If you can get a technician with a scan tool that can read O2 sensor parameters then they can tell you if it's reading properly. If you have a dead or lazy O2 sensor then it will affect the air/fuel ratio causing poor mileage and will not always turn on a CEL.
Finally, your cats may be on it's way out. The same technician can read this on the O2 sensor parameters by checking the post catalyst data.

So my old tires were 265/70-16 and the new ones are 265/75-16

MaK92-4RnR · 10-24-2009, 02:48 PM

Tune up, check the o2, keep RPMS under 3k. pretty simple things that help out. theres some modifications you can make to your truck, like exhaust. but with bigger tires and whatever else, you wont see more than 14-16 mpg... its just how these trucks are.

Kiroshu · 10-24-2009, 02:49 PM

Any codes? Tune-up? Sure your doing the gas mileage math right? Dirty airfilter? Crazy drving?

Smallwood0507 · 10-24-2009, 03:06 PM

Quote:

Originally Posted by Kiroshu

Any codes? Tune-up? Sure your doing the gas mileage math right? Dirty airfilter? Crazy drving?

Checked my gas mileage with the difference in tires and increase it to 13....still not great...but ive been driving normally...airfilter was new 2 months ago....the idiot light is not on if thats what you mean by codes

Kiroshu · 10-24-2009, 03:48 PM

13mpg for ur trucks not right..... thats about what my truck gets and its a 23 year old 22re 100% original with 31 10.50s soooo......... yea.... You have not reset the computer resently have you? or disconnected the battery recently? You may have stored or history codes which usually don't pop the engine light you need a scanner..... are you carrying a bunch of weight in ur truck? Synthetic oil? Gas leak? check fuel system and make sure its buttoned up good. vac leaks? make sure theres none.

Smallwood0507 · 10-24-2009, 08:39 PM

Quote:

Originally Posted by Kiroshu

13mpg for ur trucks not right..... thats about what my truck gets and its a 23 year old 22re 100% original with 31 10.50s soooo......... yea.... You have not reset the computer resently have you? or disconnected the battery recently? You may have stored or history codes which usually don't pop the engine light you need a scanner..... are you carrying a bunch of weight in ur truck? Synthetic oil? Gas leak? check fuel system and make sure its buttoned up good. vac leaks? make sure theres none.

Hey thanks your your help man, but i havent reset the computer or unpluged the battery....my buddy has a scanner so ill hit im up for some help this week....I do have golfclubs and a 12" sub that i always carry around, but thats not too much weight....hmm oh something else it that it is supercharged (bought it that way) and that things been on their for something like 100,000 miles + so something may be wrong there

Kiroshu · 10-24-2009, 08:44 PM

Whats the air pressure in your tires? Is it all even? Truck badly out of alignment? Brakes draging?

Smallwood0507 · 10-24-2009, 08:52 PM

Quote:

Originally Posted by Kiroshu

Whats the air pressure in your tires? Is it all even? Truck badly out of alignment? Brakes draging?

Running 36 psi which is what discount tire put in them...alignment was done last week and i dont believe that the brakes are draging at least from what ive noticed

Kiroshu · 10-24-2009, 08:56 PM

Make sure they are all 36 atleast the back ones.... if its uneven it will cause mileage to suck.... someone might be stealing ur gas......

Smallwood0507 · 10-24-2009, 09:28 PM

Quote:

Originally Posted by Kiroshu

Make sure they are all 36 atleast the back ones.... if its uneven it will cause mileage to suck.... someone might be stealing ur gas......

the tires are brand new too by the way less than 400 miles on them.....but i really hope not i do park outside every night

brian2sun · 10-25-2009, 12:57 AM

Someone wouldn't just steal a gallon or 2, you'd have a full tank in the evening and an empty tank in the morning, so I'm sure it's a problem with the truck and not your neighbors.

When's the last time you changed your plugs and wires? No S/C here, but I get 16-17 average and I've gotten as good as 19-20 on the open highway w/ a lift, 33s, and 4.88 gears. 12-13 is pretty bad even with the s/c.

JWaldz · 10-25-2009, 02:41 AM

I feel you on this one man. I noticed on my way to work last week that I burned a quarter tank in only 50 miles! 50!! That was the first quarter, too.. and I don't even have a heavy foot. I think it's time for some new spark plugs and wires, maybe some other things to look into as well. Good luck.

Kiroshu · 10-25-2009, 06:47 AM

If you have old ignition parts and or not OEM ones you can get a milage issue. If you plugs put NGKs or OEM toyota back in there for your best performance. Coils and wires maybe be expensive but if you buy them they better by OEM. Other than that theres really not much to tell you..... Your trucks not in 4wd all the time is it....? Is it extremely cold where ur at?

Smallwood0507 · 10-25-2009, 06:43 PM

Quote:

Originally Posted by Kiroshu

If you have old ignition parts and or not OEM ones you can get a milage issue. If you plugs put NGKs or OEM toyota back in there for your best performance. Coils and wires maybe be expensive but if you buy them they better by OEM. Other than that theres really not much to tell you..... Your trucks not in 4wd all the time is it....? Is it extremely cold where ur at?

I havent replaced the wires or plugs since i bought it last year so it could be due....but its not in 4wd...i do live in the foothills of colorado and i gets down to 30s at night but didnt have a problem last year...

Ironmike4x4 · 10-27-2009, 09:23 AM

Quote:

Originally Posted by Smallwood0507

i do live in the foothills of colorado and i gets down to 30s at night but didnt have a problem last year...

This just raised a red flag to me... I believe you guys in the mountain/cooler climates have a change in fuel iirc as a lot of members have said once the fuel station switch over to "winter fuel" they often get a drop in gas mileage. Apparently we don't have that problem here in SC so I'm assuming it depends on where you live. Odd thing is if this didn't happen last year then that may not be the root cause.

Have you had someone check the O2 parameters yet? From your earlier posts you have not yet changed your plugs/wires. Try that first anyways if it's due in mileage. As said before ONLY use NGKs or Denso. You will regret it if not and pay twice for it. I'm consistently getting 15.2 MPGs but I'm running 31's and have not calibrated for the larger tire sizes so I'm actually getting a false record in MPGs. Also my driving habits are much more aggressive (jack rabbit starts, in a hurry to get home, etc) so I'm creating my own low MPGs.

Parker Runner · 10-27-2009, 12:34 PM

Check your speedo/Odometer with a GPS to make sure it is accurate. It may or may not be. My speedo is a consistent 5mph off. My accord is 3 percent off on odometer.

Anyway, I get about 13 in the city and about 18-20 on the freeway below 65. At 75 it drops to 15. At 85 it drops to 13.

I am a lead foot and don't really care about mileage between 13 and 18.

I wouldn't get crazy about replacing parts unless you can prove their is a problem. Spark plugs are cheap, but coils are not. Coils can be tested.

You can spend hundreds if not thousands to chase down a bucks in gas.

Kiroshu · 10-27-2009, 04:34 PM

If you live in the moutains and its bellow freezzing alot then thats prob about right..... sadly...

Smallwood0507 · 11-03-2009, 04:54 PM

something is definitly not right my last tank was 11!!!!

Kiroshu · 11-03-2009, 06:48 PM

..... i mean i've said just about everything and you have claimed an ok on everythign so yea..... i dunno what to tell you. do a tune-up or somethin check into it further.... unless you got something freakin crazy wrong like a bent rear axle or something....

10-22-2009, 01:42 PM	#3 (permalink)
vital22re Registered User Join Date: Feb 2006 Location: kirkland washington Posts: 684	check the tune up, maybe replace the primary o2 sensor, clean the maf. how fast you driving on the freeway? keep the rpm's under 3000 __________________ 92 toyota truck 3.4 5spd 4.56 gears magna flow cat and muffler2 1/4 piping isr mod to intake 1.5 bjsfront add a leafs and 2inch lift shackles rear rancho shocks all around sitting on 265/75/r16 nitto terra grapplers

10-24-2009, 02:12 AM	#5 (permalink)
96743runner Registered User Join Date: May 2009 Location: Big Island, Hawaii Posts: 77	x2 But like others said earlier, it is probably the tires and your driving style that may be giving you that gas mileage. __________________ 1998 T4R Limited 3.4 V6 4x4 Desert Dune - Currently around 64k - AVS Rain Guards, AVS Bugflector II, Scangauge II, Running Boards Removed, Jaos Spoiler, and Wet Okole Seat Covers

10-24-2009, 02:48 PM	#8 (permalink)
MaK92-4RnR Registered User Join Date: Mar 2008 Location: Roseville, California ( NOR CAL ) Posts: 344	Tune up, check the o2, keep RPMS under 3k. pretty simple things that help out. theres some modifications you can make to your truck, like exhaust. but with bigger tires and whatever else, you wont see more than 14-16 mpg... its just how these trucks are. __________________ 1992 Toyota 4runner SR5 4x4 3.0 V6 5 Speed - Completely stock with 136k Miles. Modifications: Exhaust: Doug thorley headers, magnaflow hi flow cat, borla turbo muffler, 2.25 piping with a 3" tip Stereo: Pioneer Premier Deck, 2 12" Subwoofers, Brand new speakers all around, 1 450w 4 channel amp, 1 1000w 2 channel amp. CB Radio: Cobra 19 DX IV 40-Channel Compact CB Radio

10-24-2009, 02:49 PM	#9 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	Any codes? Tune-up? Sure your doing the gas mileage math right? Dirty airfilter? Crazy drving? __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

10-24-2009, 03:48 PM	#11 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	13mpg for ur trucks not right..... thats about what my truck gets and its a 23 year old 22re 100% original with 31 10.50s soooo......... yea.... You have not reset the computer resently have you? or disconnected the battery recently? You may have stored or history codes which usually don't pop the engine light you need a scanner..... are you carrying a bunch of weight in ur truck? Synthetic oil? Gas leak? check fuel system and make sure its buttoned up good. vac leaks? make sure theres none. __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

10-22-2009, 01:42 PM	#2 (permalink)
BigBallsMcFalls Registered User Join Date: Apr 2008 Posts: 548	bfg can drop mileage how you drive has a lot to do with it get a scangauge II and figure it out

10-24-2009, 07:20 AM	#6 (permalink)
nuke1105 Registered User Join Date: Sep 2009 Location: San Pedro CA Posts: 72	how many should i expect from my cats? I had a 4 cylinder taco and only got 80K miles out of them because they were pluged up due to lack of maintenance (my first car at 16 didnt know much). But now i have a 6 cylinder and im real anal about the service of this truck but since i bought it used how can i tell if i still have the originals and how many miles should i expect from them?

10-24-2009, 08:44 PM	#13 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	Whats the air pressure in your tires? Is it all even? Truck badly out of alignment? Brakes draging? __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

10-24-2009, 08:56 PM	#15 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	Make sure they are all 36 atleast the back ones.... if its uneven it will cause mileage to suck.... someone might be stealing ur gas...... __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

10-25-2009, 12:57 AM	#17 (permalink)
brian2sun Registered User Join Date: May 2009 Location: The Mtns, CA Posts: 506	Someone wouldn't just steal a gallon or 2, you'd have a full tank in the evening and an empty tank in the morning, so I'm sure it's a problem with the truck and not your neighbors. When's the last time you changed your plugs and wires? No S/C here, but I get 16-17 average and I've gotten as good as 19-20 on the open highway w/ a lift, 33s, and 4.88 gears. 12-13 is pretty bad even with the s/c. __________________ 97 4Runner SR5 3.4L 4x4 305/70R16 Mastercraft M/Ts on black stock 6 spokes 2.5" suspension lift ARB Bullbar ARB rear locker 4.88s Factory wood grain dash My 4th Toyota truck "If guns kill people, then pens write novels."

10-25-2009, 02:41 AM	#18 (permalink)
JWaldz Registered User Join Date: Jul 2009 Location: Arkansas Posts: 183	I feel you on this one man. I noticed on my way to work last week that I burned a quarter tank in only 50 miles! 50!! That was the first quarter, too.. and I don't even have a heavy foot. I think it's time for some new spark plugs and wires, maybe some other things to look into as well. Good luck. __________________ Silver '99 Toyota 4Runner Limited RP Black Widow Rack\|8K R.S. HID Kit\|265/75 Federal MT\|Cobra NightWatch CB\|Fosgate Sound\|24" Magnaflow\|DeckPlate Mod & KN\|Fog Mod\|Bumper Light Mod\|Altezza Tails\|Clear Corners & Turns Lift Here Armor To Come Check out my Photos

10-25-2009, 06:47 AM	#19 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	If you have old ignition parts and or not OEM ones you can get a milage issue. If you plugs put NGKs or OEM toyota back in there for your best performance. Coils and wires maybe be expensive but if you buy them they better by OEM. Other than that theres really not much to tell you..... Your trucks not in 4wd all the time is it....? Is it extremely cold where ur at? __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

10-27-2009, 12:34 PM	#22 (permalink)
Parker Runner Registered User Join Date: May 2009 Posts: 103	Check your speedo/Odometer with a GPS to make sure it is accurate. It may or may not be. My speedo is a consistent 5mph off. My accord is 3 percent off on odometer. Anyway, I get about 13 in the city and about 18-20 on the freeway below 65. At 75 it drops to 15. At 85 it drops to 13. I am a lead foot and don't really care about mileage between 13 and 18. I wouldn't get crazy about replacing parts unless you can prove their is a problem. Spark plugs are cheap, but coils are not. Coils can be tested. You can spend hundreds if not thousands to chase down a bucks in gas.

10-27-2009, 04:34 PM	#23 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	If you live in the moutains and its bellow freezzing alot then thats prob about right..... sadly... __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

11-03-2009, 04:54 PM	#24 (permalink)
Smallwood0507 Registered User Join Date: Apr 2009 Posts: 54	something is definitly not right my last tank was 11!!!!

11-03-2009, 06:48 PM	#25 (permalink)
Kiroshu Registered User Join Date: Oct 2007 Location: wade, NC Posts: 1,342	..... i mean i've said just about everything and you have claimed an ok on everythign so yea..... i dunno what to tell you. do a tune-up or somethin check into it further.... unless you got something freakin crazy wrong like a bent rear axle or something.... __________________ My current: 1986 Toyota 4runner SR5 EFI 4cyl 2.4L 22RE 5-Speed 242,000 Miles 95% Stock __________________ (Still working on restoring her) My old: 1988 Toyota 4runner SR5 EFI V6 3.0L 3VZ-E 5-Speed 302,000 Miles All stock (sold)______________ (Was my fastest truck i miss her...) My old: 1989 Toyota 4runner Non-SR5 EFI 4cyl 2.4L 22RE Automatic 231,000 Miles (sold)______________ (was my quietest and slowest yota.)

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search