12mpg?!

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BanditKoval
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Joined: Mon May 20, 2013 1:29 pm
Location: Wisconsin, USA

12mpg?!

Post by BanditKoval »

lol so my 89 xr has a ranger cam and a straght pipe exhaust and i have calculated i get 12mpg... WHYYY xD i go 150 miles gas light comes on then another 30-50 and my car is out of gas... is it the cam or maybe is there something else wrong.
1989 Merkur XR4Ti (Red):
  • -2.3l Turbo (new head, ranger cam, m11 turbo)
    -157k miles
    -C3 Auto
    -3" inch exhaust no cat w/ resonator
1995 Ford Mustang GT (Green):
  • -5.0l 302ci V8
    -154k miles
    -3.73 gearing, 4 speed auto
    -2.5" true dual exhaust no cats
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Esteban
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Location: San Diego

Re: 12mpg?!

Post by Esteban »

Not the cam. It's actually very good with gas.
Sounds like you're addicted to boost, that's all.
We've all been there.

What RPM do you cruise at? Maybe you are running in open loop all the time. Bad O2 sensor, bad ECT sensor? TPS calibrated correctly?
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dubbuzz
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Re: 12mpg?!

Post by dubbuzz »

My xr also has the c3 three speed auto. It gets terrible mileage on highway (maybe 14?) but gets better (about 18) in the city. Going 65 mph on the highway and mine rides at about 3700 rpm and the turbo is always spooled up to 0-5 lbs. Driving in town I keep it in third and it rides at about 1800 rpm at 35 mph.
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Esteban
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Re: 12mpg?!

Post by Esteban »

You shouldnt be spooling when cruising down the highway. Im in vacuum even at 80mph
Larry Velk
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Re: 12mpg?!

Post by Larry Velk »

Ron, your car was a Ford Motor Co. titled car we bought when it was still under warranty (first private owners). The wife and I kept records from maybe 17k to when we sold it to you. I don't think we EVER got more than 25mpg and when it was 15 below zero it sometimes dropped to 12mpg in stop and go below zero use. Average over 20 years on your exact car was maybe 17mpg with almost only suburban use. Short trips, but not stop and go.
Now that it's warmer if you aren't getting 17 to 19mpg there is something not quite right unless you are in the throttle too much. Best guess would be a leaking fuel pressure regulator or leaking injectors. Double and triple check the ignition timing. Sometimes we forget that XR's have air cleaners, you may want to check that. I think I put a K&N in your car and they need to be cleaned.
'86 928, black, 5sp, red full leather, 55k
(daily driver!)
'91 FZR 1000
'64 XKE FHC, in a thousand pieces
2003 BMW Ci (just like an XR!)
'89 XR, red family car
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