# 300kms to a full tank wtf?
**URL:** https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602
**Category:** SON240sx Automotive
**Created:** [March 27, 2012, 2:35pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602 "2012-03-27T14:35:56Z")
**Posts on this page:** 20
**Page:** 1
### Author:  [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)
#### Post date: [March 27, 2012, 2:35pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/1 "2012-03-27T14:35:56Z")
hey guys only getting 300 or less to a full tank on a stockish sr setup how can this be? 02 sensor maybe?
---------- Post added at 05:35 PM ---------- Previous post was at 05:35 PM ----------
and i know i should be getting 550-600 easy
---
### Author:  [@sharpe\_corners](https://forums.speedlife.net/u/sharpe_corners)
#### Post date: [March 27, 2012, 4:02pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/2 "2012-03-27T16:02:53Z")
is your bov vented to atmosphere?
---
### Author:  [@crud](https://forums.speedlife.net/u/crud)
#### Post date: [March 27, 2012, 4:41pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/3 "2012-03-27T16:41:12Z")
I vent to atmophere and still get over 600km.
question : how long have you had this engine ?
also do you engine break alot?
---------- Post added at 11:39 PM ---------- Previous post was at 11:39 PM ----------
I vent to atmophere and still get over 600km.
question : how long have you had this engine ?
also do you engine break alot?
---------- Post added at 11:41 PM ---------- Previous post was at 11:39 PM ----------
I vent to atmophere and still get over 600km.
question : how long have you had this engine ?
also do you engine break alot?
---
### Author:  [@agent240sx](https://forums.speedlife.net/u/agent240sx)
#### Post date: [March 27, 2012, 5:17pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/4 "2012-03-27T17:17:43Z")
I vent to atmophere and still get over 600km.
question : how long have you had this engine ?
also do you engine break alot?
---
### Author:  [@nate10](https://forums.speedlife.net/u/nate10)
#### Post date: [March 27, 2012, 5:45pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/5 "2012-03-27T17:45:00Z")
My bov is vented to atmosphere and I engine brake quite often, still manage to get 500+ km to a tank.
---
### Author:  [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)
#### Post date: [March 27, 2012, 6:38pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/6 "2012-03-27T18:38:26Z")
yes it’s vented out, ever since i put a new after market 300zx fuel filter not oem, new heat ranger 7 ngk spark plugs and click eco full syn oil it has been like this, aprox 2-3 weeks. but i don’t think any of that would make it this bad? also ever since i put a light weight fly wheel and 4 puck clutch it has been even worse as well and makes alot of noise. do you think it could be that i need a ecu and a good dyno tune?
---
### Author:  [@Singh](https://forums.speedlife.net/u/Singh)
#### Post date: [March 27, 2012, 8:58pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/7 "2012-03-27T20:58:49Z")
werd, I got a rich (safe) apexi fc tune, at 10psi, drive a little on the aggresive side, engine brake or heel toe, and i still get 400-450km/s city/hwy, 550 hwy only
Maybe your sr is overdue for a proper tune up.
---
### Author:  [@sharpe\_corners](https://forums.speedlife.net/u/sharpe_corners)
#### Post date: [March 27, 2012, 9:09pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/8 "2012-03-27T21:09:35Z")
7 Ranger plugs bro.
---
### Author:  [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)
#### Post date: [March 27, 2012, 10:02pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/9 "2012-03-27T22:02:25Z")
> [@sharpe\_corners](#):
>
> 7 Ranger plugs bro.
you think the plugs could do it? they are the iridium ones and come in 6 7 and 8 and 7 are for mild hp witch im like around 230-240 to the wheels
---
### Author:  [@Singh](https://forums.speedlife.net/u/Singh)
#### Post date: [March 27, 2012, 11:43pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/10 "2012-03-27T23:43:36Z")
Dylan’s right, i forgot about that. Its still to cold to be running such a cold plug. My car would misfire even when it was 20 degrees outside, until it was fully warmed up, i was running bkr7e’s.
Swap to some cheap bkr6’s and see what happens, they are like 20 bucks. I don’t see what your running such expensive plugs anyway.
Better to run cheaper copper plugs and change more often.
---
### Author:  [@crud](https://forums.speedlife.net/u/crud)
#### Post date: [March 28, 2012, 4:02pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/11 "2012-03-28T16:02:37Z")
stay away from those iratateium(iridium)plugs .nothing will finish rings faster than engine braking .heel and toe to the point that your passengers can’t feel it. my engine ,16 years old,(SR) 160 psi,all cylinders . that was yesterday.my motorbike 260,000 km would still lift front wheel why? perfect downshifts. more important than even oil change
---
### Author:  [@Mr\_Phonso](https://forums.speedlife.net/u/Mr_Phonso)
#### Post date: [March 28, 2012, 4:09pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/12 "2012-03-28T16:09:51Z")
> [@crud](#):
>
> nothing will finish rings faster than engine braking .heel and toe to the point that your passengers can’t feel it. my engine ,16 years old,(SR) 160 psi,all cylinders . that was yesterday.my motorbike 260,000 km would still lift front wheel why? perfect downshifts. more important than even oil change
I can’t really understand the point you’re trying to make. So engine braking is bad for piston rings? Next sentence you say perfect downshifts are so important, which is pretty much engine braking.
---
### Author:  [@crud](https://forums.speedlife.net/u/crud)
#### Post date: [March 28, 2012, 4:40pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/13 "2012-03-28T16:40:36Z")
rev match (heel and toe ).engine is not a brake .over time you will use up engine much faster than if you were to match engine speed to road speed. this principle is easier on engines tolerances from bottom end to top end components .it’s not hard to grasp,really
---------- Post added at 11:40 PM ---------- Previous post was at 11:34 PM ----------
read second sentence in my first response .it’s all right there in a nutshell
---------- Post added at 11:40 PM ---------- Previous post was at 11:40 PM ----------
read second sentence in my first response .it’s all right there in a nutshell
---
### Author:  [@Mr\_Phonso](https://forums.speedlife.net/u/Mr_Phonso)
#### Post date: [March 28, 2012, 5:18pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/14 "2012-03-28T17:18:54Z")
I always thought the purpose of rev matching was to engage the engine to the correct road speeds to use it as a brake. Hence engine braking.
So rev matching is okay, but using the engine as a brake is bad for the piston rings. Okay, got ya.
---
### Author:  [@Driftacular](https://forums.speedlife.net/u/Driftacular)
#### Post date: [March 28, 2012, 5:25pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/15 "2012-03-28T17:25:43Z")
I got 650 to a tank…
yah change your plugs to cheap copper plugs brah like the people say
---
### Author:  [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)
#### Post date: [March 28, 2012, 5:39pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/16 "2012-03-28T17:39:42Z")
but with the 6 range i was getting much better the iridiums are what’s recommended for the sr20 no? plus what about a new oem o2 censor i never changed it even when the swap was done still stock one from japan
---
### Author:  [@danbikes](https://forums.speedlife.net/u/danbikes)
#### Post date: [March 28, 2012, 6:34pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/17 "2012-03-28T18:34:16Z")
Seems like there’s a lot of BS in this thread… lol.
I don’t know about you guys, but my injectors shut off when I let off the throttle and engine brake.
I run 9 heat range race plugs with 850cc injectors, atmospheric BOV and can still get 550-600km to the tank if I do mostly highway and don’t rip it, granted, they don’t like cold weather/not being properly warmed up, I will give you that much.
And engine braking causing premature piston ring wear? Last I checked, your oil pump doesn’t stop turning when you let off the throttle, so I don’t see how you could damage them…
Then again, what do I know.
EDIT: also, lightweight flywheels tend to give you shit gas mileage also, due to the lack of inertia, so the engine has to work harder to keep itself spinning, if that makes sense at all.
---
### Author:  [@240sx\_nismo](https://forums.speedlife.net/u/240sx_nismo)
#### Post date: [March 28, 2012, 6:52pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/18 "2012-03-28T18:52:54Z")
> [@danbikes](#):
>
> Seems like there’s a lot of BS in this thread… lol.
>
> I don’t know about you guys, but my injectors shut off when I let off the throttle and engine brake.
>
> I run 9 heat range race plugs with 850cc injectors, atmospheric BOV and can still get 550-600km to the tank if I do mostly highway and don’t rip it, granted, they don’t like cold weather/not being properly warmed up, I will give you that much.
>
> And engine braking causing premature piston ring wear? Last I checked, your oil pump doesn’t stop turning when you let off the throttle, so I don’t see how you could damage them…
>
> Then again, what do I know.
>
> EDIT: also, lightweight flywheels tend to give you shit gas mileage also, due to the lack of inertia, so the engine has to work harder to keep itself spinning, if that makes sense at all.
yes see ever sine i put that on i also have had worse gas mileage, but i thought it makes the engine work less do to less rotation mass?
---
### Author:  [@danbikes](https://forums.speedlife.net/u/danbikes)
#### Post date: [March 28, 2012, 8:13pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/19 "2012-03-28T20:13:52Z")
Well, initially, yes, less weight helps the engine (which is why the response is so much better). But once it’s spinning, the weight the engine spins also helps it continue spinning. So if you lessen that, the engine has to work harder itself to make up for it, hence bad gas mileage.
Sorry if it’s a bit unclear, I’m not the best at explanations sometimes, lol.
---
### Author:  [@trickey1991](https://forums.speedlife.net/u/trickey1991)
#### Post date: [March 28, 2012, 9:28pm UTC](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602/20 "2012-03-28T21:28:17Z")
RB20DET 250whp 425km full tank highway/city driving. Highway 540km .
[Next page](https://forums.speedlife.net/t/300kms-to-a-full-tank-wtf/221602.md?page=2)