crappy mpg

[Bruce Wayne]

I got about 15.2 mpg right before getting the diz rebuilt,new plugs and plug wires. still just over 15 mpg after that. what gives? I used to get 17-18. could it be the colder weather is making my mpg's go south? it's been in the high 30's to the teens since the poor gas mileage. or did I get some bad gas? (don't Eat at Joe's)

[ValleyHappy]

it could be the cold weather. your motor runs in enrich mode when started up and until the coolant warms up (more gas)....also the motor runs most efficiently at full warm up temp......this takes longer to reach in cold weather.

if you don't see other symptoms, this could be the deal...or others

check your tire pressure lately? cold weather reduces tire pressure.....more gas
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09 Suzuki SX-4 Crossover

[Bruce Wayne]

just had the tires rotated and air pressure checked last week. changed the oil and filter too. it takes about 4-5 miles (on the freeway) for my motor to get up to temp,and it's only 12 miles to work.

[ValleyHappy]

the fact that your motor is still warming up for ~ half of your commute may be enough to ding your mpg during the winter. your commute sounds very similar to mine and my mpg went from ~18.5 in the summer to ~16.5 in the winter......takes almost a full ride to work for my van to warm up in the winter.....not so in the summer. this is my guess. it's also my first winter with it as a dd, so we'll see how things shape up in the spring during the warmer months.
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09 Suzuki SX-4 Crossover

[devesvws]

i have a 87 4 spd non camper and i get 17-18 mpg and have not been going over 60 mph. yes the t-stat is stuck open so it never gets above the first mark. but even last summer at normal temp range i might get 18-19. thats a long way from the 18-22 mpg i was geting before july of 06. i posted a much better mpg then http://www.thesamba.com/vw/forum/viewtopic.php?t=136963&postdays=0&postorder=asc&start=0 the number one reason i think my mpg is down is the 10% ethanol blend gas that is the only thing that has changed. i watch my mpg like a hawk and have become very bummed out over all this.

[Surf Trip'n]

I was getting 17 mpg prior to a full engine rebuild. Afterwards I was getting as low as 12 mpg. After the engine broke in (3 Months) and I changed my driving habits (55-60 mph) I got better gas milage. I have a 87 Camper (Automatic) and got 19.85 mpg on one trip obviously with the wind behind me, but on average 16 to 17 mpg.

[Bruce Wayne]

I was zipping around at 70mph getting 17mpg. im thinking I should let up on the right foot a little and see how it goes. I forgot about the 10% ethanol thing.that started recently didn't it?

[flnettles]

I have put $8000 in repairs into this 85 Vanagon, changed engine (put in an 84), am getting about 6pmg 2 VW shops have recommended I replace the air idle control valve. Picked up a used one on EBay (may be a mistake) but new ones are very expensive. Won't be able to get back to the shop till next Friday, does anyone have any thoughts on this? It is supposedly on it's 3rd engine. Cosmetically it's great.

[Wildthings]

Not sure when the change was made, but I thought all 85's had Digijet and used and aux air regulator instead of the idle stabilizer valve. If your mechanics are trying to tune you engine as if it were a Digifant system instead of a Digijet that might account for your poor gas mileage.

[flnettles]

That might be, but it has an 84 1.9 engine after the last change....

[Wildthings]

You need to have it tuned to the type of fuel injection that is installed on it. The year and size of the engine are not that critical to the tune up compared the the specs of the specific fuel injection.