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2004 chevy trailblazer_ls
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Discussion Starter · #1 ·
Hey guys,
ya'll know i finally joined the 20's club :woot:and i LOVE 'em, i cant go back :nono:
one thing tho i need to ask you guys who had them for a while, hows your mileage ? mine SUCKs BIG TIME, i use to get 450 Kilometers from a full tank, now i get 350 only :eek: is that normal ?should i just live with it or what ? and i had a new fan clutch installed " if that has any thing to do with it " i prefer my old one which had the old glue-thingy they new one is just noisy as hell :duh:
waiting for your input fellas :undecided
 

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I wouldnt contribute that great of mileage loss just to the new wheels and tires..


how long has it been since you replaced the fuel filter? or cleaned the throttle body?
 

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2004 chevy trailblazer_ls
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3,900 Posts
Discussion Starter · #4 ·
OMG ! are you guys serious ? :eek::sadcry:
last TB clean was really close, i think 300Kilometers ago, and never changed the fuel filter as far as i know :undecided:rolleyes: but i have the stupid throttle body that recently had the gasket replaced since the old one was melted, would that do such a thing ? a bad gasket ???:confused:
 

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maybe you need to be a little lighter on the gas pedal.......:crackup:don't drive it like you stole it........LOL.........
 

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2003 gmc envoy_slt
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Hey guys,
ya'll know i finally joined the 20's club :woot:and i LOVE 'em, i cant go back :nono:
one thing tho i need to ask you guys who had them for a while, hows your mileage ? mine SUCKs BIG TIME, i use to get 450 Kilometers from a full tank, now i get 350 only :eek: is that normal ?should i just live with it or what ? and i had a new fan clutch installed " if that has any thing to do with it " i prefer my old one which had the old glue-thingy they new one is just noisy as hell :duh:
waiting for your input fellas :undecided
The new fan clutch is noisy? It should be quieter than the old one. If the new fan clutch is bad ( sounds like a jet engine ), that would hurt mileage.
 

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2005 chevy trailblazer_ls
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The new fan clutch is noisy? It should be quieter than the old one. If the new fan clutch is bad ( sounds like a jet engine ), that would hurt mileage.
:iagree: should prob get that checkd out :undecided

mpg difference with 20s was not noticeable:m2:
:iagree:x2 believe it or not, on my stock 245 75 17s my rolling diameter was only 0.x" difference with my 275 45 20s...so it was comparable, they are alot heavier so maybe the weight hurt a lil but overall its a very small difference :m2:
 

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2004 chevy trailblazer_ls
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Discussion Starter · #8 ·
Funny thing buddy is i AM heavy on the pedal, but after the fan clutch change i hardly go over 2500rpm ! cuz of the noise, so i drove it for 3 tanks totally slow :no: and i got ****ty mileage :duh: thats what piss's me off :hissy:

The new fan clutch is noisy? It should be quieter than the old one. If the new fan clutch is bad ( sounds like a jet engine ), that would hurt mileage.
it is, but no pattern, like it could be parked for a week and when i start it it'll go like a jet engine for 10 min, and it could be parked for a week also and when i start nothing until i turn it off and on again :weird: just like that..
and guess what ? a am going to the dealers to pick it up as we speak for the 3rd TIME :hissy::mad::bonk: they say its fine ! i told them i had had my car for 5 years and NEVER heard that noise ever ! and they keep saying its fine..i am totally disappointed :worried: and out of ideas :( and hopeless :sadcry:
 

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2004 chevy trailblazer_lt
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I went from 17"s to 22"s and noticed NO difference in fuel mileage whatsoever. I'm not sure what's wrong. I have had the same issue with my fan, as well, however. It happens rarely but every once in a great while it sounds like a jetliner taking off. Not sure what the cause is, but it doesn't happen all the time so I am not worried about it.
 

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2002 gmc envoy_slt
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Larger wheels are a trade off. They are heavier to turn from a stop and there's more contact with the pavement, however the lower profiles tend to decrease rolling resistance slightly. I might contribute 1/2 a mpg to larger wheels, but not 3-4 mpg.

As stated above, the fan clutch should not engage and sound like a jet engine. Now the new design with the updated PCM code does run the fast faster when the a/c is on than the older design did for improved cooling. I recall several owners who mentioned it was louder with the new clutch, but quieter than when the old clutch would decide to fully engage for no reason. If you still sound like a jet, the new clutch most likely has a problem. If its slightly louder than the old clutch was on a 'good' day (when not in jet mode), but less obnoxious than when engaged and sounding like a jet, it may be fine.
 

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From 17's - 20's, I didn't notice much change.

Are you sure that you got tires that are the same overall height as the stock ones were? If not, that will throw your calculations off. (if you stock tires were 29.5" tall, the new ones should be pretty close to that)
 

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Discussion Starter · #13 ·
Larger wheels are a trade off. They are heavier to turn from a stop and there's more contact with the pavement, however the lower profiles tend to decrease rolling resistance slightly. I might contribute 1/2 a mpg to larger wheels, but not 3-4 mpg.

As stated above, the fan clutch should not engage and sound like a jet engine. Now the new design with the updated PCM code does run the fast faster when the a/c is on than the older design did for improved cooling. I recall several owners who mentioned it was louder with the new clutch, but quieter than when the old clutch would decide to fully engage for no reason. If you still sound like a jet, the new clutch most likely has a problem. If its slightly louder than the old clutch was on a 'good' day (when not in jet mode), but less obnoxious than when engaged and sounding like a jet, it may be fine.
since you mentioned it buddy, when they changed the Fan clutch they didnt update any thing !:undecided my old PCM and the new one that i tuned from PCM4LESS are both on the old 2004 program ! :rolleyes:
still, its not bothering me as much as the mileage is ! :hissy: could it be the spark plugs ? the oil ? i am hopeless at the point i think i\ll change every thing and see if there would be any improvement cuz i gave up, the dealer doesnt know $shi ! i swear here your find guys, like your self, that'll give you more knowledge that the dealer ever gave me, hell i totally belive now that they DONT know nada !:hissy::mad:

From 17's - 20's, I didn't notice much change.

Are you sure that you got tires that are the same overall height as the stock ones were? If not, that will throw your calculations off. (if you stock tires were 29.5" tall, the new ones should be pretty close to that)
the tires i got are the same mesurment as every onse here :yes: i asked they guys numres of times before i bought 'em, so i dont worry there :thumbsup:
 

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Hey guys,
ya'll know i finally joined the 20's club :woot:and i LOVE 'em, i cant go back :nono:
one thing tho i need to ask you guys who had them for a while, hows your mileage ? mine SUCKs BIG TIME, i use to get 450 Kilometers from a full tank, now i get 350 only :eek: is that normal ?should i just live with it or what ? and i had a new fan clutch installed " if that has any thing to do with it " i prefer my old one which had the old glue-thingy they new one is just noisy as hell :duh:
waiting for your input fellas :undecided
I am wondering the same thing. I really hate the stock 17" wheels and want 20". But I cannot get a straight answer from anyone on how bad the gas mileage will changed. The guys at discount tire tell me it will be a very noticable change. I only get 15 miles to the gallon around town as it is, I am not willing to sacrifice any lower than that. My TB is a LS 2007 not sure if different year models get different gas mileage.
 
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