We just picked up a 99 Max GLE Auto. Stock. Stock rims (15s) Our second tank. Mostly short drives. Country some city.
319Kms to 42L = 13L/100KM = 17.9 MPG (US) = 21 MPG (Imperial)
That Sucks!
What is yours? Transmission? What are your mods?
NOTE: Do not really want to know miles to a tank. Your mileage to a tank may be when you fill up the car when it runs out of gas, or at the 1/2 way mark.
319Kms to 42L = 13L/100KM = 17.9 MPG (US) = 21 MPG (Imperial)
That Sucks!
What is yours? Transmission? What are your mods?
NOTE: Do not really want to know miles to a tank. Your mileage to a tank may be when you fill up the car when it runs out of gas, or at the 1/2 way mark.
Original EPA mileage on 99 GLE was 21 city/ 28 hwy. But those numbers were under the old, less realistic EPA calculations.
Senior Member
24.5- 26.5 mpg on Premium, 5 spd. se, driving like I stole it at least once a day. No codes, new knock sensor, look in the stickies to find info on various sensors and tune up stuff you may want to do.
That is really poor mileage, ecu is probably retarding the timing (bad knock sensor) for starters.
That is really poor mileage, ecu is probably retarding the timing (bad knock sensor) for starters.
Thanks for the tip. I will check that out. Other tips welcome. Still like to hear other's mileage though and mods.
Senior Member
i have a 98 GLE. i was getting about 20-21 mpg for a while, then i got an intake and i just checked and it was about 24.
Senior Member
$hitty, same as yours and i replaced the ks a month ago and all my fluids are fresh. but, what do you expect from a 171,00 mile motor that i beat on most days??? gotta love it, gas goes higher and higher and i don't care.
Senior Member
$hitty, same as yours and i replaced the ks a month ago and all my fluids are fresh. but, what do you expect from a 171,000 mile motor that i beat on most days??? gotta love it, gas goes higher and higher and i don't care. 

132000 miles
I used to get 14 (200 mi per tank), but then i put air in my tires and cleaned my icv and tb and get about 22 (350 mi per tank), with a few bits of spirited driving in there once in a while.
I used to get 14 (200 mi per tank), but then i put air in my tires and cleaned my icv and tb and get about 22 (350 mi per tank), with a few bits of spirited driving in there once in a while.
Senior Member
166k
Auto
Stock
21MPG when I drive like an ***
25MPG when I drive nice
City/highway mixed
CEL for rear o2 sensor.... but I don't care till I smog
And yeah... when I had my intake I was averaging like 1-2mpg more.... but the noise got annoying to me. Mostly just the sound at idle. Sounded like there was a faucet WFO under my hood.
Auto
Stock
21MPG when I drive like an ***
25MPG when I drive nice
City/highway mixed
CEL for rear o2 sensor.... but I don't care till I smog
And yeah... when I had my intake I was averaging like 1-2mpg more.... but the noise got annoying to me. Mostly just the sound at idle. Sounded like there was a faucet WFO under my hood.
that sounds exactly what my max gets. around 320 on a tank. 330 if I baby the pedal, but thats no fun!!!
Recently I just cleaned out the IACV, throttle body, Intake manifold, Lower intake manifold, put new rings and seals on my injectors, just kind of cleaned out the fuel rails (they were taked apart at the time anyways so why not, cleaned the egr, and a new filter.
I havent been able to drive it on a full tank or even put more than 10 bucks in at a time but I am EXPECTING much higher milage for this amount of work. I know that changing o2 sensors helps because they loose their affectiveness over time
Recently I just cleaned out the IACV, throttle body, Intake manifold, Lower intake manifold, put new rings and seals on my injectors, just kind of cleaned out the fuel rails (they were taked apart at the time anyways so why not, cleaned the egr, and a new filter.
I havent been able to drive it on a full tank or even put more than 10 bucks in at a time but I am EXPECTING much higher milage for this amount of work. I know that changing o2 sensors helps because they loose their affectiveness over time
Newbie - Just Registered
The last time I checked after running down a tank and filling up, doing the math and such my stock 95 GLE gets 19-21, depending on how ludicrous my driving gets...This is even without having cleaned my TB or IAVC (which I plan to do since I know for a fact its never been done).
EDIT:180k miles on the engine
Soon though I intend to do some things such as upgrade the y-pipe/cat converter/exhaust, and I was wondering how that effects MPG if at all. Increase? Decrease? Nil? Anyone know from experience?
EDIT:180k miles on the engine
Soon though I intend to do some things such as upgrade the y-pipe/cat converter/exhaust, and I was wondering how that effects MPG if at all. Increase? Decrease? Nil? Anyone know from experience?
i drive pretty hard and am gettin low 20s (22-24) 80% city driving automatic. plugs and knock sensor did quite a bit.
Quote:
That is why I asked for mods along with the mileage. Then we can see a pattern with what mods.Originally Posted by johnnyd
Soon though I intend to do some things such as upgrade the y-pipe/cat converter/exhaust, and I was wondering how that effects MPG if at all. Increase? Decrease? Nil? Anyone know from experience?
basically, 17 is horrible.. MODs really dont improve or kill your milage. maintenaice will restore your milage. first thing you want to check are your sensors esp the knock sensor, and 02, bad sensors can retard airfuel mix and advance timing and cause bad milage. these can actaully cause your timings to suck so you get less milage and less hp.
after that then check for clean air filter, spark plugs, fuel filter, properly inflated tires, use 91 octane at least, and clean your TB.
if you do all that and your engine is not shot, you should get about 21-25 mpg mixed driving, with an occasional lead foot. if you get more than 25, your averageing 65 on the freeway with a good draft from a big rig.
if your still getting bad milage, your got more serious problems with fuel delivery, or a contaminated tank.
after that then check for clean air filter, spark plugs, fuel filter, properly inflated tires, use 91 octane at least, and clean your TB.
if you do all that and your engine is not shot, you should get about 21-25 mpg mixed driving, with an occasional lead foot. if you get more than 25, your averageing 65 on the freeway with a good draft from a big rig.
if your still getting bad milage, your got more serious problems with fuel delivery, or a contaminated tank.
ohh..i meant non force induction mods. your in a whole nother boat when your not NA
Senior Member
Quote:
Yes we areOriginally Posted by Max Noob
ohh..i meant non force induction mods. your in a whole nother boat when your not NA

I get 17-19MPG, basically all city driving, 5spd, only mods are an intake cone and coilovers.
Quote:
I agree with that. My mileage on my Daytona Shelby went up quite a bit going to a 3" Mandrel, catless system. If I remember correctly from about 27ish to low 30s. It has since been averaging around 35-36 (Imperial) with a few other tweaks. Have not done a new dyno run, but I suspect in the mid 200s whp with the new exhaust mani and turbo.Originally Posted by Max Noob
ohh..i meant non force induction mods. your in a whole nother boat when your not NA
Junior Member
I get about 25 MPG average, most of my driving is on local highways but maybe 12 miles a day on the interstate.
New knock sensor, new air filter, cleaned the throttle body, make sure tire pressure is right. I, too, drive like the young punk I am a few times a day, but for the most part I try to take it easy on the accelerations and decelerations.
New knock sensor, new air filter, cleaned the throttle body, make sure tire pressure is right. I, too, drive like the young punk I am a few times a day, but for the most part I try to take it easy on the accelerations and decelerations.
Quote:
Thanks for the clarification, I get 16mpg when I drive reasonably. I was just about to tell you you're nuts but you clarified yourself!Originally Posted by Max Noob
ohh..i meant non force induction mods. your in a whole nother boat when your not NA
Senior Member
in summer with steele 15's on my 96 5 spd i got 31 at best like 90% highway (55-60 MPH) and 25 for a low with 27 for a adverage
with my A33 wheels on which weigh about 15 lbs more a piece I got 27 at best and 23 on adverage
but now in the winter (i'm in minnesota) i put on my 15's again and I get 24 adverage. but not with this crappy snow we have now.
with my A33 wheels on which weigh about 15 lbs more a piece I got 27 at best and 23 on adverage
but now in the winter (i'm in minnesota) i put on my 15's again and I get 24 adverage. but not with this crappy snow we have now.
I'm getting around 19-20 Mpg, all city (but all weekend and evenings so almost zero rush hour and a fair bit of that is innercity freeways), brand new platinum plugs, brand new air filter, CEL for O2 sensor and Knock sensor lit, I know the air in the rear tires is a bit low, 91 octane premium.. temps have been between +50 and -7 F during this time. 1996 GLE Auto, 214k kms/133k miles, fully stock.
note: I've been driving like a granny to check out the mileage.. very little pedal stomping... sadly.
note: I've been driving like a granny to check out the mileage.. very little pedal stomping... sadly.
Senior Member
I average about 21-22 mpg. I don't use premium, though. And that's a lot of highway. When I drive the streets, mine drops to about 20 if I don't floor it every time a light turns green. If I do blast off from every stop, it'll drop to 18 or 19. I've even seen 17 on some tanks. Not in a very long time, though. I've been riding easy over the past couple of years. At 187K, I don't wanna be too hard on my car.
Quote:
note: I've been driving like a granny to check out the mileage.. very little pedal stomping... sadly.
your knock sensor code is being thrown? that will steal a couple miles per gallon right there..not because your car is consuming more on a static level, but you overcompensate on the pedal because of the weak pull in low end 2nd and 3rd gears. you end up consuming more gas for the same performance.Originally Posted by DizzyEdge
I'm getting around 19-20 Mpg, all city (but all weekend and evenings so almost zero rush hour and a fair bit of that is innercity freeways), brand new platinum plugs, brand new air filter, CEL for O2 sensor and Knock sensor lit, I know the air in the rear tires is a bit low, 91 octane premium.. temps have been between +50 and -7 F during this time. 1996 GLE Auto, 214k kms/133k miles, fully stock.note: I've been driving like a granny to check out the mileage.. very little pedal stomping... sadly.
Newbie - Just Registered
right now im getting about 18-20 mpg and soon i hope it will get better with the intake i have to install this week also my check engine light is on and i had it checked once and it something about fuel flow or somthing and also if i go below a 1/4 of a tank my car will stall.
Senior Member
That's bad mileage Herm.
As the advice in here points out...there's simple stuff that can be done to significantly improve performance & mileage on the 4th gens with over 100K miles.
Do it first, then mod away!
BTW: I have 160K and match the best mileage report in this thread so far (when I'm not carving up traffic every day).
(No CEL, Clean TB & IAC, No mods save for front strut bar.)
As the advice in here points out...there's simple stuff that can be done to significantly improve performance & mileage on the 4th gens with over 100K miles.
Do it first, then mod away!
BTW: I have 160K and match the best mileage report in this thread so far (when I'm not carving up traffic every day).
(No CEL, Clean TB & IAC, No mods save for front strut bar.)
Senior Member
I forgot to tell what codes. Well, I have an Evap canister purge code and something else I think. I have three. The evap, knock sensor, and something else. I should check and see what else has come of late. Anyway, I get my 21-22 even with knock sensor code. I don't plan on fixing it. Ever. A former Nissan tech buddy of mine says that the knock sensor will rarely turn the "check engine" light on, so I wouldn't fail emissions test from the start simply for the light being on. Now my rusty exhaust is another story.
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