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Sat May 14, 2005 6:45 pm

Ok. I am getting some terrible gas mileage in my baja daily driver. I just filled up and calculated my mpg as 11.7. What the heck is up with that. I only drove to and from work, taking it very easy on the car. No unnecessary acceleration or anything. What is normal for a vw. I have an 1835 with a centermount 36mm Dellorto. It was just tuned up 3 weeks ago. I put all new plugs, wires, cap, rotor, coil. I have a .009 with a Crane high intensity ignition module. I had an issue with my needle valve which was fixed by a local ACVW shop and they set the timing and tuned the carb up after I put all the new ignition parts on. Also there is a new fuel filter and some new fuel line between pump and carb. It has new oil and a new transmission. What the heck is going on? I never really calculated it before this tank. It always goes down quickly. Is that normal? I was thinking I was getting like 17 or so, but less than 12. Ouch. However, my speedometer is a bit off as a result of larger front tires. About 5 mph at 60mph. So I am actually traveling a bit further than the odometer gives me credit for. So being very generous I'll throw an extra 2mpg on there and go with 14, which still sucks. What can I do? What does everyone else get. At $2.50+ a gallon, that adds up quick.

Sat May 14, 2005 6:47 pm

Also. I have 4.37 gearing. So it's not geared for highway, but I didnt drive more than 10 miles on the freeway this last tank.

Sat May 14, 2005 9:25 pm

Time to pony up for an EFI set up.

Sat May 14, 2005 10:15 pm

EFI is quite an expense. No doubt it would pay for itself in time at the current cost of gas, but what is normal for a car and engine like mine? That cant be normal. Thanks.

Sun May 15, 2005 12:07 am

What can I do to increase fuel economy? I cant spend much on the car right now, but if there is something that would increase mpg dramatically it would be worth it. Is 20 mpg achievable in a baja? I thought that would be possible, but it appears that I am far from that for some reason.

Sun May 15, 2005 1:13 am

I get roughly 27 mpg. I have a 1600sp with a 30pict-1. Trans is a stock 1974 with a 3.88n ring and pinion, not the best for the desert but I get around. Top speed is about 85 mph. The best mileage so far has been 35 mpg, fully loaded with 3 people, going to the last Score Parker 400.

Sun May 15, 2005 2:16 am

My fuel mileage isn't that great either, and I think that is what you would find to be common with baja owners. My car is running a 1915 with dual carbs (single barrels). I think I generally run in that 10-12mpg range. I honestly think vwclass11 is the exception to the rule here. Even stock cars don't usually achieve such exceptional mileage. However, he sounds like he is running a fairly anemic setup. Suprisingly, the air cooled VW isn't as much of a fuel miser as some would like to think.

For good fuel mileage, that mechanical advance distributor isn't helping you. Tall heavy tires hurts things even worse. The only thing in your favor is the single carb, but your Dellorto is considerably larger than stock so if you push on it the fuel is really going to flow. Factor that in with a larger displacement, perhaps a more agressive cam with larger heads and that cool sounding merged header and you ultimately get poor mileage. Join the club...haha

In your cars defense, you should get a better baseline on your fuel consumption. Your pretty much guessing. The first thing is to figure out how far off your odometer ratio is. That is going to be a big key, especially over the distance you travel on a full tank of gas. What size front tires are you running? Is there an area that you can check your odometer for accuracy? On the freeway they often post speedometer check areas. Get these things factored in before you buy that EFI setup that baja5 suggested.

SHMO

Sun May 15, 2005 3:56 am

When I had a 1775 with a single 2 bbl in my Baja, I was getting around 15-18mpg on road.

When you pulled the plugs what did they look like? The single 2bbl has to run rich, but some of the setups I've seen were much richer than necessary.

Sun May 15, 2005 8:58 am

I get crappy fuel economy also, Probably because I am running really rich.

Sun May 15, 2005 1:41 pm

My plugs were fouled and sooty, but that was mainly a result of my needle valve taking a dump on me and it was dumping raw fuel to the point that the car would stall and not run. That fixed, and "professionally" tuned, I am still getting junky mileage. I bet my speedometer/odometer is further off than I think it is as well. I do have a big rear tires, larger displacement, etc. etc. as listed by SHMO, so I dont expect honda civic mileage or anything like that. But 18 to maybe 20 driving conservatively would be nice. I will try to test my speedometer to see how far off it is. Is the margin of error a constant with speed or does is increase exponentially with speed? Meaning. If it's 5 mph off will at 10mph will it still be 5mph off at 70 or will it be more off. My brain isnt working and I am not sure. The odometer error should be proportionate to the speedometer error.

Next: I know that a .009 mechanical advance distributor is not the best option for mileage and drivability. Can I run something like an SVDA with my setup. I have vaccum ports on the dellorto that are capped off, but with a larger than stock carb and motor, the vaccum settings would not be the same as stock, so how would an SVDA or similar dizzy advance correctly? It's a daily driver, so anything that would improve mileage and drivability would be a nice option.

Third: I dont have heat risers on my carb intake. The intake has ports for the risers, but the risers are not there and the riser plates on the exhaust dont funtion. I dont know if they are clogged or welded or what. There is no block off plate, but no exhaust gas comes out. I know that lack of manifold heat greatly decreased fuel atomization and consequently drivability, escpecially in colder weather. I would therefore expect a lack of manifold heat to have a similar negative effect on fuel mileage as a result of insufficient atomization with the centermount intake manifold. Is that correct? And if so, would switching manifolds and adding heat risers increase MPG noticably. Luckily it doesnt get below freezing hardly at all here, but I would like to be able to take the baja to Tahoe in the winter, where I would definately need manifold heat to keep from icing, so purchasing a new intake would be a nice option anyway.

Sorry this is so long. Thanks in advance for any input available. Take care.

Sun May 15, 2005 1:47 pm

Also, I did not mention this yet, but I have no idea what jets or anything the carb has. Or any internal specs on the motor such as cam, heads, etc. I bought the car already setup. It runs great, but the mileage is poor. I know there are ton of variables (which unfortunately, I don't know) but does anyone know what size jets I should have in there? And is it possible to tell what jets I have by looking at them? I will be rebuilding the carb soon, as I just got my rebuild kits in this past week.

Sun May 15, 2005 2:23 pm

What tranny gears are you running? (stock typeI swing??)
You already said 4.37 R/P correct?
What rear tire diameter?

Sun May 15, 2005 2:30 pm

I am not sure on jetting specs for your Dell. Actually every car is going to be different. Even the same car in different areas will have different jetting needs. For proper jetting you need to take into account the motors needs and variables such as temprature, elevation, air density, bla bla bla. If your jetting is off by a bunch, that can be most of your fuel mileage right there. Installing a vaccum dizzy might be a good thing to try, along with a pertronics or compufire kit. But to be honest, I highly doubt you will get to that 20mpg range with your car. Not without going backwards on performance.

Take a tape measure to your front tires. How tall are they?

SHMO

Sun May 15, 2005 3:43 pm

Any improvement is better. 20 is just goal. I doubt I'll get that, but the closer the better. I have 325's on the back and I think 175's up front. I think they are 28" tall. I will go measure in a few minutes. I do already have a compufire electronic deal in there. I have a typr 1 IRS with 4.37 R&P. It's a built beast from KCR with EVERYTHING, but close ratio gears.

Will a vaccum advance distributor work with my setup? Which vac port do I connect to? Any thoughts on the heat riser manifold advantage? I will most likely rebuild the carb soon, and maybe I can figure out what jets are in there. Are they labeled or something? Thanks again for everyones help. I will be driving to Sacramento for Bugorama in two weeks, and I would like to get some of this figured out before then or that will be an expensive trip.

Sun May 15, 2005 6:59 pm

I know what you mean on the mileageI get more MPG out of my chevy truck pulling a trailer with the bug on it. I dont have a fuel guage so I always go with the 10 miles to a gallon method. But I am a lead foot with 33 inch rear tires. I am in the process of installing a toyota 20R motor, So well see if it improves..

Sun May 15, 2005 7:14 pm

I did measure the front tires. They are 27.5 inches tall if that helps at all. I will try to some testing on the freeway with the mileage markers sometime this week. Hopefully a combination of little improvements will add a few MPG for me.

Sun May 15, 2005 8:19 pm

I've got my 2110 w/ dual 44 IDFs up to 19 MPG on the highway, but at freeway speeds, my mileage takes a nose dive, due mostly to my 5.38 to 1 R&P 002 trans.
Even with a 009, I would think 20 MPG is very doable. I think jetting will play a huge part in getting you better mileage. You can rent a wideband O2 sensor from A/C.net to accurately check the jetting and get it dialed in.

Sun May 15, 2005 8:43 pm

Well,

if your tires are 27.5 and I THINK stock VW tires are about 24 inches, (Double check that measurement because I am not exactly sure) you would be getting pretty close to 14mpg.

14mpg aint really all that bad for your current setup, however you do want it better. First thing I would do is double check your timing. Then check your jetting to make sure you're not running in a rich condition. You originally mentioned the fuel filter, but said nothing about the condition of the air filter. A dirty air filter can wreck havoc on your fuel mileage. Check that! After those bases are all covered you will have to look towards mechanical changes. The first thing I would consider changing would be the distributor if your carb does have the needed vaccum line. A 009 isn't the best for most street driven applications. Not only will you notice some MPG improvement by switching to vaccum advance, but you just might notice better drivability and performance.

SHMO

Sun May 15, 2005 9:08 pm

i have read that you need to do a full tune on the engine before you can expect to accuratly tune your carb....something to keep in mind.

Sun May 15, 2005 11:16 pm

The air filter is clean as well. Just cleaned it 2 weeks ago. Any thoughts on the manifold heat concern? So as long as my carb has a vaccuum port, a vacuum advance distributor will work? Even though it's not a stock motor or carb?