Hi Everyone, heavy wagon / SUV 'project' Volvo V70 XC
 

Hello!

New to the board and I wanted to introduce my project (oh, and I'm Mike from central PA.)

It's a 2001 Volvo V70 XC, automatic (5-spd manu-matic), AWD, 2.4 liter inline 5 low-pressure turbo car. 150,000 miles but in well maintained condition. I currently average about 21mpg over a full tank - this rarely varies at all and my calculations always match the built-in computer almost exactly. Shorter trips can be as low as 16mpg. This is mostly my to-from work average. On a longer weekend trip to the beach, I can average somewhere in the 24 to 25mpg. Looking forward to tracking this more closely.

Also looking forward to learning about a few well-known and maybe a few fringe technologies to improve this. My end goal is hopefully somewhere in the 15% to 20% improvement range (I know, lofty goal!) and if this is more biased toward the local commute vs. highway, I'd be fine with that. I'd like to limit myself to a 3 or 4 year payoff for modifications and I'm very comfortable with advanced auto mechanics. Budget will likely be capped at about $3,000 usd.

Limits - the car must remain usable as a wagon to haul my kids (3 and 4) and my wife and our 2 dogs safely to a destination, possibly with a load of cargo or even the occasional trailer in tow. It can look funky doing it but I don't want to disturb the inherent safety of the car (not going to chop the roof and change pillar angles, for instance.) I'd like to retain the AWD if possible. I've gained what seems like 1 to 2 mpg avg. over a summer season with the center driveshaft removed but never did an A-B-A comparison in the same weather conditions. I may make that a seasonal maintenance item.

Things I'm most interested in:

* starting with lower viscosity synthetic lubricants at any maintenance intervals

* leaner AFR, increased static compression ratio (milled head) and supplemental water injection to keep things from knocking - I've read that water injection is really only effective on diesels but I wonder why trimming back fuel and advancing timing (reducing power) but cooling - I feel like big gains could be made here but nobody has really documented it very well for FE gains. :confused:

* possible stand-alone engine management to mess with fuel/timing rather than just trying to fool the fuel management

*lighter, narrower wheels and LRR tires (this falls outside the budget since I'll need tires in a year or two anyway and I'd wait until then.)

*lowering the vehicle approximately 1.5"

*airdams, undertrays, other aero mods (custom grill, etc.) possibly some of the rear hatch aero conversion stuff but only if it doesn't kill visibility.

*possible downsizing to Volvo 1.9T 4-cyl instead of 2.4T 5-cyl

*slight possibility of completely removing all AWD components and going to manual transmission but then why not start with a FWD car?!?

I've also always had a radical idea of supplementing with an electric drive for the rear drivetrain and decoupling it from the front. The cost/size/weight of batteries is the limiting factor on that one since payback would be closer to 10 years :eek: so I've never really seriously considered that one for very long.

I'd love to hear other feedback about similar 4,000lb vehicles with huge frontal areas and big hatchback dropoffs. Thanks everyone! Looking forward to the journey! :thumbup:

Hey brik welcome! even though you are just starting you are well on your way, in my opinion over half of your modding is done in your head, or as we say the adjusting the nut behind the wheel.

You've listed some rather involved modifications. What's your plan of attack? Easiest first makes sense. (I suspect you can approach 15% better economy before having to get into the engine.)

EG: does the car have roof racks? A block heater?

We have another member who turned his Honda CRV from 4wd to 2wd by removing the center shaft, but he also wasn't able to do controlled testing.

Welcome to the forum!

Welcome! Your location says central PA - care to get more specific? Harrisburg area, I'm guessing?

Well, my truck weighs 4000 lbs and has at least as much frontal area as your Volvo..... But I have 2 WD, 5 spd manual, and a 2.8L 4 cyl engine.

You might start with stuff that doesn't cost much - DWL, DWB, grille block, tire pressure, front end alignment, and rear end alignment if your car has IRS. Your 15% to 20% goal is conservative.

What RPM is your engine at 55 or 60 MPH?

Thanks everyone for the warm welcome and feedback.

Yes, Harrisburg area. Camp Hill. Being from NJ, I've really enjoyed adjusting to living here.

Roof racks, not really but I left the OEM side rails on as I do occasionally mount crossbars to carry longer pieces of lumber, bikes, etc. The XC model has quite a bit of cladding added to it. I wonder if removing that for more subdued/smoother V70 bumpers and other pieces might help.

No block heater yet. Sounds like a good easy thing to start with, along with cleaning my kids' stuff (and some of my hoard) out of the garage so I can park inside with my wife's Prius C. :rolleyes:

I currently run the stock tires at 38psi. They're rated for up to 40 on the sidewall. Could go a few more, I guess. My commute to work today was (based on computer readout) 19.7mpg and 21.7 on the way home. The same routes net 52 and 62 in the Prius. Needless to say we carpool whenever possible.

I love being brought back to reality and reminded to get the low hanging fruit first. Thanks for that reminder and keep it coming - repeatedly- seriously! I have a tendency to daydream and lose sight of the smaller things that are actually more attainable.

I've been itching to lower the car, though, so that will probably happen along with replacement of a few clunking sway bar links and the front and rear alignments. Grill block and engine block heater will go to the top of the list.

The more complex / expensive items were really listed just for proof of concept ideas for me to tinker with. If I can get to 15% without them, great! I think they'll stay on a long term project list until some new technology arises that makes my current car completely obsolete or I move to a place with better public transportation.

Okay, now I have to go back and re-read the stickies because I'm not sure what DWL and DWB are. :o

Thanks again for all of the tips! What a great active forum! :thumbup:

raise your tire presure for starts.
I would worry about narrow tires......safty of the kids in a loaded car?
But go a size up and go lrr.

Taller but stock width/load rating LRR tires it will be. Thanks! I got to thinking about taller tires today but the 2.31 final drive made me shy away. There's so much low end torque, though, it seems like it will be a good mod.

It's a pretty well geared car. I can cruise at 60mph around 1500 rpm, IIRC. I see mostly 45mph and under driving. Spend a LOT of time at 1100rpm, honestly.

Hmmm...yes, will need to practice driving with load. Drive without brakes, well, I drive like a granny since we've had the kids and try to rarely use the brakes but sometimes even coasting I need to get this tank down to normal speeds. Is it suggested to downshift at those points vs. braking? No more boy racer, for sure. I'm getting better at timing the lights and cresting hills, etc. The hybrid is actually helping me a bit with DWB technique since it keeps me in 'EV' mode more often.

Off to read up some more on these topics...