1st part is oil, car's got 72k miles on it. going to go to mobil 1 10w-30 for the summer. then back to 5w-30 for the winter? AC Delco pf35 filter. sounds good?

2nd. was getting just bout 110 miles a tank. replaced O2s and right now its 50 miles with 3/4 tank left with like 90% city 10% highway and a fairly heavy foot at times. which is a ton better than before. Now in the effort of try to squeeze some more mileage per tank, any other sensors (other than O2) that might also reduce gas mileage, i know the MAP is one of them... all suggestions are welcome, thanks!

 

with the oil, engine having that many miles on it why change back and forth with weights, ide keep it at 10w30 all year around, if you have a heavy foot you wont get good mileage, thats my problem

 

Your oil/filter selection sounds great

The MAP sensor may slightly effect ignition timing but it'd have to be really messed up to reduce gas milage. The most critical sensor on the car is the MAF sensor. If this is dirty (especially from running something like a K&N filter) then cleaning that can improve gas milage and throttle response! It's a sensitive piece of equipment so take care when doing so

 

110 mile per tank? That's pretty bad. I can almost get that many miles before it gets off the Full mark.

 

haha yeah shoebox I know, its down right horrible, so you can see why now that I got some decent mileage going again that I want to get every mile I can....even if it means switching my foot to the unleaded varity. 110miles before it leaves full, I assume its due to guage inaccuracy?, my guage seems to be accurate so far. I will check the ole MAF soon to make sure its clean. Engine seems to be strong, but I have nothing to compare it too, and I have no f-body buds...but it pulls better than a v6, thats for sure. All suggestions are welcome so keep them coming, thank you.

btw: plugs/wires are bout 6months old, fuel filter about 1 month and O2s are about 1 week.

 

mine doesnt leave the full mark til the 100 mark. I usaully get about 270 if I have a heavy foot but if i drive easy I get about 310 thats with highway/city driving. Usaully if its all city i get about 250 or so

 

Wow, I would probably shoot myself if I had only 110 miles per tank. I would go broke in a second.

Similar results for me, usually I get about 250 miles per tank on ALL city miles, and about 350 on ALL highway miles. (I take some pretty long trips sometimes, so yes they truely are all highway.) Using good old 93 octane. Then again, I only have a lead foot when I need to (like when that Rustang is next to me at the light, or at the track ).

As far as oil goes... I've run Mobil 1 5W30 in my car all the time. Should I be running 10W30 during the summer? Will it make that much of a difference for me? I don't have that many mods yet (see sig).

 

i got a heavy foot too... but i still get about 200 miles a tank... bout 50-60 before its off F...

maybe thats the automatic and 2:73's worken for me tho?

 

something i don't get:

people are always like i use 5w 30 in the winter (obviously... for the colder temps) and then they switch to 10 w 30 in the summer...

maybe im wrong on this, but i always thought
that the higher number represented the amount of heat the oil could take or whatever
so if you switch to 10w30 from 5w30
all your really changing is the amount of COLD the oil is good for

 

wow you guys really get 250 miles/ tank? I get 100 miles/ tank

 

Cold makes oil run thick, 5w is thinner than 10w so it will get where it needs to go quicker, in the cold.

 

if your car is on stock heads and cam and only getting 100mi/tank, you've got some serious issues. my m6 94 Z was getting 320/tank driving on extremely curvey roads at unsafe speeds. the car had 116000mi on it, new plugs and no cat. my new a4 97Z is getting about 280/tank on the same curvey roads at the same speeds...it's completely stock and i just did a tuneup (plugs/wires/intake oil fix/fuel, oil, air filters/lubes). the only thing i didnt' do was o2 sensors (if i replaced those, would my mileage go up?)
i hope you've got a 8 second car if you;'re getting that bad of mileage!

and on a side note, i don't know about 96's but i believe the 97's have fairly accurate fuel gauges. the one in mine and my friend's 97's are much different than the ones in my old 94.

 

90% city and a lead foot explains your gas concerns

 

could be Trey, could be... I also cleaned my MAF today with some spray-on contact cleaner, went from a dark grey to a nice shiney metal again....drove it around for a bit and filled it up with Sunoco 94 octane...unfortunately i was able to add 7.5 gallons of gas and 70 miles on the trip counter. so it went from full tank almost 1/2 tank in 70miles? and i wasnt even driving that hard since i was tryin to monitor my fuel. man I got serious serious issues. Its like there's a gas leak or something, but I cant smell it or see it. Im very worried. I will have to take it to a GM Goodwrench place or something to have it checked out. I dont have the proper tools to scan it and such.

btw: yes its stock, only has the mods in my sig. and mkent Im glad your Z is doing good. I remember your post about when you wrecked you 94 and was concerned about not being able to get another 1.

 

hey, where did you get that MAF cleaner from? and what kind is it? i have never cleaned mine and probably need to. thanks.
dave