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View Full Version : Fuel Mileage..whats the usual and how can you improve it?


twitchy
04-22-2003, 11:17 AM
I have a 93 240SX SE which is basically stock, the only modifications are the removal of the factory intake baffle as well as a slightly larger exhaust pipe (although it has a cat and goes into the stock muffler)

My question is this:
What should my car get for fuel mileage (IE Range. Its a 50 liter tank, so how many kms?) and

How can I improve it


Considerations:

-I change oil regularly (5000 kms, semisynthetic)

-Gearbox and Diff fluid just changed last month

-I drive the car enthusiastically, but usually shift at 4000 rpms or so, once in a while give it some stink, rarely sees redline

-I think it would be the same on most cars, but the fuel gauge drops more slowly in the middle 2 quarters than the top or bottom quarter

-Slight slop in front end, maybe it needs an alignment, or something, nothing major though.

-Drove with all my friends from Sudbury to Brit and back. The trip consisted of roughly equal parts highway and city driving. Comparing all the cars to one another, I had the worst mileage of the 4 on that trip.

2002 Mustang GT: V8 4.6 liter. Used quarter tank
2002 Mustang GT: 4.6 liter, open exhaust. Used quarter tank
97 Tiburon FX: 2 liter I4. Used quarter tank
87 Mustang 5 liter. Used quarter tank.
My 93 240SX used a little over half a tank on the same trip!! (all cars manual with 50 liter tanks)


Has anyone tried mileage-boosting products? Could I need a new O2 or MAF sensor? ANy ideas as to why my car burns more gas than an engine twice its size would be appreciated!

Thanks

Dousan_PG
04-22-2003, 11:20 AM
check/change/replace
fuel filter
fpr
plugs and wires
oils
check your tb
air pressure in tires

um..that's all i can think of, i knw theres more

twitchy
04-22-2003, 11:25 AM
Originally posted by dousan36
check/change/replace
fuel filter
fpr
plugs and wires
oils
check your tb
air pressure in tires

um..that's all i can think of, i knw theres more

Thanks, but whats a fpr or a tb?

As well the fuel filter is also new, forgot that.

Dousan_PG
04-22-2003, 11:29 AM
sorry
fpr=fuel pressure regulator
tb=throttle body

sykikchimp
04-22-2003, 11:32 AM
fpr = fuel pressure regulator
tb = throttle body

also replacing the o2 sensor is a good idea.

The 240sx was rated at 21mpg city, and 28mpg hwy. Anything in that range is acceptable.

I get about 12mpg at the track. So with hard driving, she'll drink the gas.

AKADriver
04-22-2003, 11:34 AM
Oh man... you wouldn't believe how badly my car was sucking gas at VIR! And blowing it out the exhaust...

Anywhere in the 20's is normal

I'd also check the MAF and the electrical connection to the MAF.

twitchy
04-22-2003, 11:35 AM
How can I check the Fuel Pressure Regulator?

is it something I just have to change?

sykikchimp
04-22-2003, 11:38 AM
It's rare that the fpr will be causing your problem. Check the other stuff first, if that doesn't help, then find out more about the FPR and possibly even clogged fuel rail, and injectors

240 2NR
04-22-2003, 01:43 PM
Mixed city (not stuck in traffic)/ highway my 93 240 gets around 27/28 mpg in the summer. Winter time it tends to drop down around 24.

By my fuel guage that's about 100miles per quarter of a tank.

DuffMan
04-22-2003, 03:52 PM
I have some 205/65/15 tires i'm going to stick in the back. 5% improvement in highway gas milage, here I come!

Apparition
04-22-2003, 09:07 PM
Only cause I know Highway 11, were you passing people more than the other drivers? I found driving north through the two-lane stuff, I was just guzzling gas like crazy rifling it past those damn transport trucks. For me, driving from hamilton to north bay, I get great mileage except for that last hour on highway 11, due to ups/downs and the constant slowing down, speeding up, etc.

240 2NR
04-22-2003, 09:21 PM
Originally posted by DuffMan
I have some 205/65/15 tires i'm going to stick in the back. 5% improvement in highway gas milage, here I come!

Holy huge sidewall Batman!

mrmephistopheles
04-22-2003, 09:30 PM
The best way to save gas is to give the muscles in your right leg a rest.
I got as high as 31mpg when I was driving across the country..

240Driver39
04-23-2003, 12:45 AM
i usually get like 21miles/gal around the city, but got 34miles/gal driving home from virginia...i was amazed haha, and i was makin good pace the whole time too.

Yoshi
04-23-2003, 01:28 AM
wow, I didn't realize the difference was so significant.
SR= 20city 26highway
KA= ?/? I think it was pretty close last I checked... so I guess my KA is not doing so hot :/

Warwick5s
04-23-2003, 10:15 AM
Originally posted by Yoshi
wow, I didn't realize the difference was so significant.
SR= 20city 26highway
KA= ?/? I think it was pretty close last I checked... so I guess my KA is not doing so hot :/

mine either :(

Dream240
04-23-2003, 11:28 AM
Originally posted by mrmephistopheles
The best way to save gas is to give the muscles in your right leg a rest.
I got as high as 31mpg when I was driving across the country..

Yeah, ain't that the truth. I drive frequently from San Fran. to LA, and I get about 350-375 to the tank (14.75 U.S. gal) going about 75-80.
You'll notice that 240s guzzle up the gas when you have to break from 75 to 50 and then accelerate back up from 50 to 75 constantly-like when passing those slow diesels.