I got a quick question about some other 4runner gas mileage readings, i have an 88 4runner sr5 v/6 with 265/16in tires with a flowmaster and im getting about 14 mpg in the city i know thats s#!? for a 3.0 liter v/6. my 2500 mega-cab dodge gets 16 in the city and that has a 5.9 liter diesel. thanks if you got any reponse

Is it an auto?, if so that is about normal.

If it is a 5-spd, it should do better than that with stock tires. It may be time for a completet tune-up.

That's what I'm thinking too; tuneup time!

Your tires are taller than stock; don't forget to compensate for that (I think the 265's are about 10% bigger than the 235's that the truck came with)...

So that would put you into the 15.5-16mpg range for city. Nothing unusual about that, especially if it's an auto.

EDIT: need to consider section width, ratio and wheel size in this math, which I did not do. My bad.

car is a 5 speed and a full tune up done 6 months ago

I missed the tire size being 265's, I think 225's are stock. BKG is right about the mpg being closer to 15.5-16mpg's.

Did the full tuneup include cleaning the injectors, a new fuel filter and a compression check/valve adjustment?

How old is teh O2 sensor, from what I understand the OBD1 sensors get lazy with age and tend to run rich.

Was the truck getting better mileage before, or is it a new rig for you?

What pressure do you run in the tires?

Car was purchased from friend who did basic tune-up like plug, wires, water lines, valve adjustment, and a few other small things except for the injectors and fuel filter but running injector cleaner through system right now to hopefully help a little

Fuel filter, o2 sensor, OBD1 sensors i no idea when replaced if replaced

i run about 50 psi on PRO-COMP ALL-TERRAINS

265/16's are ~32" tall... at 50 lbs, possibly closer to 33, even. That's closer to 20% larger than stock.

Running injector cleaner really doesn't do much if the injectors are dirty. I used to run the stuff through mine, and when I had them rebuilt the tech said they were filthy. You could lose some % mpg if the injectors aren't atomizing the fuel, though might not be enough to warrant pulling them and having them rebuilt.

With the age of the truck and no idea when/if the O2 sensor was replaced it would be a good idea to replace it, shoudl run somewhere between $50 and $100 for a denso, the dealer charges a little more.

However after you adjust for the difference in tire size(if you weren't before), youir city mpg isn't that bad. You could improve it some by changing your driving style. Try to keep the rig moving as much as possible, i.e. don't gas up to a stop, coast as much as you can. Don't do jack rabbit take-offs, since Toyotas are heavy rigs(to engines), you can waste a lot of fuel through heavy acceleration from stops. Also keep the tranny in a gear that keeps your rpms up around 3k(shift at about 4k), this is the beginning of the 3.0 power band, running below this point is wasting fuel.

Quick tire calculation:

New tire size / old tire size = % of Difference

Example;

265 / 225 = 1.17777 or a 17.8% increase in tire size.

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