New Members: Welcome Thread

[DelbertWrench]

Hi all:
New to gassavers and looking for other VW drivers to learn gas saving tricks. I drive a 2000 Golf gas 1.9 L automatic getting 24 to 29 mpg and a '95 Dodge Dakota V-6 standard trans getting a steady 21 to 23 mpg for the last 6 years.
I need help with tweaking the VW to improve mileage.
Delbert

[theholycow]

Welcome!

It's surprising to see that your VW is automatic and your Dodge is stick...one would usually expect the opposite.

I had a 2008 VW with the 2.5l I5 and I had really great results. My route was combined city/highway; the EPA combined rating was 25 and I was up to 44 when I got rid of the car. However, I'm not sure that everything I did with it would apply to your 2000, and mine was stick.

The most important thing to tweak is your driving. However, a quick easy free tweak to the car that will provide immediate results is increased tire pressure.

[rocketjohn]

I tried a few kits and plans on HHO units and after much experimenting decided I could do better. 1St cell overheated and eventuall exploded ! No real problem though fitted in a safe place to an old 1.9D diesel Toyota pickup. Anyway after over 2 years experimenting and designing plus a eureka moment have developed a scaleable wet cell that can produce 6lpm at less than 10 amps! This is not lies! Not sure where to go from here with it? Let me know what you think. In spain Europe so time difference can be 8 hours! Good luck.

[shonus]

Hello to everyone from humid south Florida, I don't know how any of you can block off your radiators without your cars overheating. I wouldn't dare try that here or much less remove my ac. I own a 96 Saturn sl1 and recently went back to a short ram intake after using a 62" long custom cold air intake with my average mpg being 28 mostly because of how fast I would accelerate since i experience no loss of low end power with my setup. I do miss the way it would start pulling at around 40-45 mph and if I do not see a nominal increase in FE I will be switching back to the CAI. My goal for now is 37 mpg.

[theholycow]

Welcome!

How much did your FE drop when you changed to the CAI from stock? I wouldn't expect much more than getting that back from your short ram.

You're getting 30 now so 37 is definitely not out of reach, simply using efficient driving techniques (and I'm not talking about snail-pace acceleration or plodding along slowly).

Blocking off the radiator sounds bad, but keep in mind that vehicles are designed with lots of margin for the worst case scenario: Badly maintained partially clogged radiator towing a badly dragging trailer at max GCWR in Death Valley in the worst part of summer. (Ok, that is a slight exaggeration for some vehicles, but dead-on for others.) I have blocked radiators on my 2002 GMC and 2008 VW without any significant change in coolant temperature; the huge, high-capacity cooling systems really don't need much flow to keep cool with normal driving, let alone efficient driving.

[shonus]

Thank you, and actually I have gone through so many different intake designs and my final CAI design was all 2.75" aluminum tubing, mandrel bends, and a 3" inlet performance air filter with a velocity stack. I had the tubing tuned so well that everytime I let off the gas with the ac on I could hear the intake vacuum hiss from the filter. My biggest FE killer has been my right foot haha. Before I switched back to short ram my last fill up with aggressive city driving, ac on the whole time, and 75 mph on the interstate still netted me 30 mpg
I'm glad you mentioned about the snail pace because I tried it and it drove me crazy.
That is interesting about blocking off the radiator, but I swapped for a higher temp thermostat and my needle goes past half a lot so I will keep my radiator fully unblocked

[shonus]

oh and that 30 mpg was also when the front of my rear stock spoiler was 1.5" from the trunk and the rear was 5" from the lip of the trunk. I raised it and angled it to try and create a little more downforce.

[theholycow]

In 3 1/2 years of extensive effort at saving fuel I've been able to ease myself into obeying the speed limit, although that's been more about the cost of speeding violations than the cost of fuel...a major fiasco from one ticket knocked some sense into me. However, I rarely drive slow for fuel economy; I find my fuel economy elsewhere. Some people don't have so much difficulty driving slow, so they find it easy to gain fuel economy by slowing, but it's not the only way.

You convert fuel into energy, and there's not a whole lot you can do about making that more efficient (if your goal is saving money). Sure, there's things like hotter thermostats, warm air intake, and grill/radiator blocking, but those things tend to be either ineffective or minor improvements.

What you can do is think a lot about where that energy goes. You can adjust tire rolling resistance with increased inflation (which comes with a large set of other advantages like better handling, increased failure resistance, and longer treadwear); aerodynamics (like that spoiler); braking (by not using your brakes, whose job it is to discard energy that you'll just have to replace again soon); and wasted engine revolutions (by using high gears for cruising and coasting in neutral with the engine on or off when appropriate).

Those are just quick descriptions of my most commonly used concepts. Techniques learned here, as with those learned in other places for other purposes like racing, should really only be practiced within the confines of safety, the law, and your own personal comfort level. You can't concentrate on driving efficiently if you're worried about your safety, the police, or your car.

[shonus]

I do have a question about tire inflation my uncle has worked on Saturns for years as a mechanic and has worked for Cadillac, VW, mitsubishi, and now currently Chevy and he told me to only put 35 psi in my tires even though they are rated at max 44. Should I inflate them to the full 44 or leave them at 35? currently I am driving around with 38

[theholycow]

There's no universal number. The proper inflation is recommended by the manufacturer for the OEM tire size, and GM often specifies 35. On most vehicles it is marked on a label in the door jamb.

However, keep in mind the priorities that manufacturers have. The most important thing is to sell cars, and every potential little bit of smooth ride comfort helps sell a car on a test drive. They tend to specify the minimum.

The maximum marked on the tire is, in my opinion, a good maximum. Realistically it is safe to exceed that significantly (as long as handling remains good) but it could potentially expose you to liability in a post-crash investigation. Your optimal pressure may be somewhere between the car manufacturer's recommendation (assuming you're still at OEM size) and the tire's maximum.

I've been using increased pressure for about ten years, long before I cared about fuel economy, and it has only brought me good results. The usual bugaboos are false or grossly exaggerated. Automotive tires don't pop from being inflated a few PSI beyond their maximum like bicycle tires; you have to go hundreds of PSI too high before that happens. Road hazard resistance gets better, not worse, as the tire gets increased resistance to snakebite damage from the rim. Handling, in my experience, is almost always improved (due to the stiffer sidewall, in spite of the reduced contact patch). Wear is improved too; with extreme overinflation you can get center wear but total tread life is not reduced, you just have tread left on the sides when otherwise the whole tire would be bald.

I can go on and on but it's better to ask about specific concerns and test it for yourself.

Here's a few vehicles I ran/run at increased pressure...

1997 Pontiac Grand Am, ~2700 pounds, 205/55-16, 44psi. This is the car where I discovered the advantages; I switched tire brands and was not happy as the tires wore at the edges, handled sloppily, and had premature sidewall cracking. Got them replaced (same brand and model) and cranked it up from 35 to 44 and the next set lasted forever.

2002 GMC Sierra 1500, ~5000 pounds, 245/75-16, 60-80psi instead of 35. 80psi is too high in the rear tires with no load in the bed; handling gets skittish and it gets easy to spin the rear tires.

2008 VW Rabbit, 3000 pounds, 195/65-15, 51psi instead of (IIRC) 30. Handling was greatly improved. Centers wore maybe 1/32" ahead of sides; the center wear bars smoothed with the tread when the sides were barely ridged above the wear bars.

1980 Buick Lesabre, 3500 pounds, 205/75-15 and 225/75-15, 38-60psi depending on the tire and how ballsy I feel. Haven't run it long enough to have wear results, only about 17,000 miles.