ok i have a 95 rodeo 3.2 v6 2x4 getting only 18 mpg.

the oil stays at about 30psi when not at idle
at idle about 5 to 10psi. i dont know if its a bad guage or pump
but it runs perfict just bad mpg


any ideas?

 

p.s. this was on the highway at 50mph!!!!!

 

For reference my '97 gets 24.

Run some fuel injector cleaner through it.
Check the air filter.
Check the throttle body is clean. Mine was 'not' and the shop pulled off the ~1/2" between the filter body and the intake, plugged in some spray cleaner and with the engine running let rip. While smoke everywhere, but a clean throttle body. Reconnected everything and it's been fine since.

 

as far as oil pressure, mine doesn't do much better than that at idle...probably depends on weight of oil used, miles on engine, etc...
As far as only getting 18 mpg? Terrain makes a big difference...you say it was on the highway at only 50mph? What gear were yhou in? Even if in 5th gear, it's not optimum conditions to get great mileage. Here in michigan on the highway (70-75 mph flat ground no AC) i can get 24mpg, but around town (where i'd be more likely to be driving 50mph or less) i'd be happy with 18....if i lived in wv or colorado where there are mountains to make your engine work harder i don't think i'd get such good mileage on the highway

The shop probably ran "sea-foam" through your engine...it's a product that has been out for 40 years and it's available at any parts store for about $8. I have run it through my jeep, smokes like the devil...never really noticed any great performance increases (but heck, it is a jeep)
Some will run 1/3 of a bottle through the throttle body, 1/3 in your crankcase, and 1/3 of the can in the gas tank...run for 250 miles or so and then drain your oil and change filter and refill with your oil of choice.

 

This was a spray can they plumbed into the intake. The throttle body had a black sticky sludge in it, which this cleaned out. Didn't take long at all.

 

we took a trip of 250miles one way most of the way was 50 mph but some of the way was around 70 mph

 

i have a small car that gets 35mpg at 70mph but 47mpg at 50mph

 

That oil pressure seems on the low side. Ours is ~25 idle and ~50 at cruise.

 

Sounds about right. Most mileage claims are done at 55 with driver only under controlled conditions.

 

could low oil pressure caus low millage?